Houseplant Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Aerate
[verb]
Aerating the soil means breaking up the soil with your hands or a tool to allow air and water to move more freely through it. You can use a chopstick, skewer, fork, pencil, fingers, etc. You may need to do this if your soil is compacted.
Aerial roots
[noun]
Aerial roots are roots that grow from epiphytic, lithophytic, and parasitic plants that grip onto support, pull water from the humidity in the air and nutrients from whatever they grab onto. Some aerial roots will break down what they are gripping onto, to grow deeper and to create nutrients.
Aerial roots grow from the nodes along the stem, usually only as little nubs. They differ from terrestrial roots in that they are usually thicker and have a skin that protects them from damage or from losing water. They can also reach the ground and grow into the soil or water, becoming the terrestrial roots we are used to.
Air plants
[noun]
Air plants are plants in the Tillandsia genus and in the Bromeliaceae family, making them bromeliads. They are epiphytic plants that have specialized leaves that take in moisture and nutrients. Air plants only grow roots enough to cling to whatever they are growing on.
Albo
[name]
Albo is a nickname or common name for a few different cultivars of variegated plants, mostly aroids. The name is typically used for cultivars with a few large, solid sections of variegation as opposed to many small, speckled sections. Albo is derived from “albus” which is the Latin word for white.
Annual
[adjective]
As opposed to perennial, annual plants die at the end of their growing season, usually after they’ve produced their flowers and gone to seed. For some plants, it is programmed into their DNA; they produce seeds and die off, making space and fertilizer for their seeds which will lay dormant until the spring. However, some plants that are sold as annuals are labeled as such because they will die in winter, but they can be perennial (continue growing for years) in warmer climates.
Anthocyanins
[noun]
Anthocyanins are a group of chemical pigments found in living plants that cause purple, pink, and red coloring. Leaves with anthocyanins still have chlorophyll or they wouldn’t be able to do photosynthesis, but the anthocyanins sometimes mask the green coloring. Anthocyanins are used to communicate with animals (“Eat me!” “Don’t eat me!”), protect the plant from temperature extremes or too strong of light, absorb green/blue light that the chlorophyll doesn’t absorb, and more. Examples of plants with anthocyanins include: Tradescantia zebrina, the underside of most Calathea species’ leaves, and most flower petals as well as fruits like blackberries, blueberries, and strawberries.
Areoles
[noun]
Areoles are spots along the length of a cactus that appear as small, often fuzzy, bumps. This is where the spines, flowers, roots, or new growth sprout from. Areoles set cacti apart from all other succulents. They may appear fuzzy due to trichomes (plant hairs), which are harmless or sometimes, like in the case of the Opuntia genus, glochids (tiny spines) which will cause irritation.
Aroid
[noun]
Aroid is a nickname for plants from the Araceae family that grow similarly shaped flowers with a thick center stalk and one rigid shield-like petal (most commonly seen in Peace Lilies or Anthuriums). They all have the ability to root in water but appreciate moist, airy soil with things like bark, pumice, peat or sphagnum moss and coco coir. Genera in the aroid family include Epipremnum (Pothos), Monstera, Spathiphyllum (Peace Lilies), Alocasia, Anthurium, Aglaonema, Zamioculcas and more.
Arid
[adjective]
Arid is an umbrella term for plants like to dry out, including caudiciforms, succulents, and cacti. Arid plants are found in hot areas with lots of sun and low humidity. This is not a biological term so there are no hard boundaries to the category.
Axillary branching
[noun]
Also known as lateral branching, axillary branching is the pattern of growth where the main growth line keeps going, with new growth starting from the side of the stem. It occurs in the growth of the plants as well as in the growth of roots. Axillary branching is the more common method of branching seen in Ficus elastica “Rubber Tree”, Philodendron hederaceum “Heart Leaf Philodendron”, and most other plants. The other type of branching is dichotomous.
B
Bark
[noun]
Bark is a tough layer of outer flesh that woody plants grow to protect the living flesh inside. Bark is made of dead cells of the plant and can vary widely in thickness and structure, getting thicker as the plant matures. Bark protects the thin layer of living flesh on the outside of the stem of woody plants called the cambium.
Biodiversity
[noun]
Biodiversity is the variation of living organisms in an area, or ecosystem. It’s not only variation of different organisms — plant, animal and other — but also the genetic variation in a group of the same organism. Biodiversity in an ecosystem is important because every plant and animal has a role in this balanced process called the circle of life and an ecosystem can struggle or fail if one piece is removed. Genetic biodiversity is important because it keeps harmful genes from being passed down and makes the species more adaptable to disease and environmental changes. Biodiversity is why you can’t have children with your cousins: your child could have a third arm or something more fatal because you and your cousin share the same obscure gene for third arms. If you and your whole family were clones, then you could also easily be taken out by the same disease.
Bonsai
[adjective], [noun]
Bonsai is a traditional Japanese art that translates to ‘tray planting’. It involves taking an immature plant or cutting of a plant, growing it in a shallow container, and strategically shaping it over decades of growth to resemble a miniaturized mature tree/plant. It was traditionally done with woody plants like fruit trees, coniferous trees, and the extensive Ficus genus, but it can be done with any branching plant including succulents like Pachira aquatica ‘Elephant Bush’ or Adenium obesum ‘Desert Rose’. The practice of bonsai involves pruning the branches and roots to encourage bushiness and keep it small, as well as using wire and other support to influence the shape and growth of the branches and roots.
Bromeliad
[noun]
Bromeliad is a nickname for plants in the Bromeliaceae family. People mostly use the name bromeliad to refer to plants in the Vrisea genus, Neoregelia genus, and others that have bright colors and patterns with a large cup in the center to hold water, but air plants and pineapple plants are also bromeliads
Bulb
[noun]
Bulbs are root structures, meaning they grow underground, that store water and nutrients, much like tubers or corms. The word bulb is often used to describe tubers and corms, as well as rhizomes, but they are all separate structures with similar functions: they form to support the plant through changing conditions but they are used by plants to self-propagate. Bulbs are able to survive dormant for long periods underground or out of soil in cool, dry conditions.
C
Cacti
[noun]
Cacti is a name for plants in the family Cactaceae; the singular of cacti is cactus (the opposite of humans; I and us). Cacti are a type of succulent and are set apart from the rest of succulents by having spots called areoles along the length of their bodies and by growing spines instead of leaves.
Cachepot
[noun]
Also known as a decorative pot, a cachepot is a pot, with or without drainage, that holds the pot that the plant is actually planted in — typically a nursery pot. If they don’t have drainage, they can be used as a saucer, or water catcher, for the plant: you can pour water into the plant where it sits and then pour out any excess water in the cachepot after the soil has had time to soak up what it can hold.
Callus
[noun], [verb]
A callus is a plant’s way of healing a wound, like a scab. It keeps in moisture and keeps out bacteria. If you are taking a cutting of a plant, let it callus over before trying to propagate it. You will know the callus has formed when the wound is dry and hard. Arid plants can take days, even weeks, to callus. Callus cells are mostly unorganized or unspecialized cells — aka meristem cells — meaning they can grow any sort of cell the plant needs so that whatever was wounded can be replaced or can function again.
Cambium
[noun]
The cambium is the thin layer of flesh around the outside of the stem/trunk and just under the bark of woody plants. Besides the usual growth points at the end of each branch and in each node, the cambium is responsible for the outward growth of the trunk. This is called secondary growth. As the plant grows, the cambium creates the cells that become the bark and the wood (which is the vascular system of the plant).
Carnivorous plants
[noun]
Carnivorous plants is an umbrella term for plants that digest bugs and animals in traps. In the case of Nepenthes pitcher plants, the trap is a stomach-like pitcher that forms on the end of the leaves. In Venus Flytraps, it is a mouth-like trap that closes when something irritates the fine hairs on the inside of the ‘mouth’. Other examples include sundews (the Drosera genus), and bladderworts (the Utricularia genus), both of which use sticky pads or hairs to capture and digest their prey.
Caudiciform
[noun]
A caudiciform, is a plant that grows a large, swollen base called a caudex. The caudex stores water and nutrients in this space to prepare for drought. It often will drop its growth when dormant, becoming a living rock or lump, and when it has the right conditions to grow again, the caudex can make new growth points from anywhere. Pruning encourages the plant to focus on expanding its trunk. There is a wide variety of caudiciforms across all different climates and families of plants, although the majority are arid plants. Examples of caudiciforms include: Adenium obesum “Desert Rose”, Stephania erecta, and Polyscias fruticosa “Ming Aralia”.
Chlorophyll
[noun]
Chlorophyll is the chemical in plants that causes the green coloring. It helps the plant convert sunlight into energy for photosynthesis. Chlorophyll absorbs all light wavelengths except for green and yellow, which is why plants appear green. Plants are sometimes purple, red, or blueish, too, which comes from chemicals called anthocyanins.
Cresting
[noun]
Also known as the ‘cristata’ or ‘monstrose’ form of a plant, cresting turns a straight line of growth into multiple writhing lines of growth that can create a shape similar to coral or brains.
Common name
[noun]
A plant’s common name, as opposed to its scientific name, is the nickname that is easier to remember and pronounce. Sometimes plants have numerous common names and sometimes a plant doesn’t have a common name.
Compaction
[noun]
Compaction happens as soil ages; the organic material breaks down and the plant sucks the nutrients out of it. What is left becomes packed together, or compacted, and less water-retentive, even hydrophobic. Sometimes it may be ready to be repotted. Sometimes you just need to aerate the soil a little bit and probably fertilize.
Compost
[noun]
Compost is a nutrient-rich, water-retentive material made of broken down organic material. It is used as a soil amendment to add organic material back into the soil and fertilize. You can make it yourself with food scraps and some elbow grease or buy soil mixes with it already mixed in. There are local composting organizations near you and they may sell their compost.
Corm
[noun]
Corms are a root structure that stores water and nutrients, much like tubers or bulbs. They form to support the plant through changing conditions but they are also how some plants self-propagate. Corms are able to survive dormant for long periods underground or out of soil in cool, dry conditions. Plants that create corms include Alocasia species and Eleocharis dulcis “Water Chestnut” (we eat the corms!).
Corking
[noun]
Corking is a change in skin texture of a plant that happens when the plant starts to get very tall or wide and feels that it needs more stability. The skin becomes harder, dry and brown in color. Corking is most commonly noticed in succulents because it will happen on the body of the plant instead of just the stem where we expect to see bark. It is not harmful to the plant even if it looks ugly.
Cultivar
[noun]
Cultivar is short for “cultivated variety”. A variety is a plant that is the same species as another plant but has a different feature, like a different variegation, color flower, or leaf shape, which happens naturally. A cultivated variety is one that has been carefully selected and created by humans, either through pollination, grafting, or propagation.
D
Dichotomous branching
[noun]
Also known as terminal branching, dichotomous branching is the pattern of growing where one growth point divides to two equal points which divide again and and continue in that manner. It occurs in the growth of the plants as well as in the growth of roots. Dichotomous branching is less common in houseplants; it’s seen in some cacti like the Mammillaria genus, some palms like Chamaedorea elegans “Parlour Palm” or “Neathe Bella Palm”, the Selaginella genus “Club Moss” and the Strelitzia reginae “Birds-of-Paradise”. The other type of branching is axillary.
Dicotyledon
[noun]
All flowering plants are either a dicotyledon or a monocotyledon. A dicotyledon is a species of plant that has two embryos (plant fetuses) in the seed as opposed to the one found in the seed of a monocotyledon. These plants have a more of a web growth pattern in the roots, the leaf patterns and the leaf veins, a specific flower and pollen structure, and about half of dicots grow wood (also known as secondary growth). Common dicots include the Schefflera genus, the Monstera genus, oak trees, and cacti!
Death bloom
[noun]
Death blooms are the flowers of monocarpic plants that signal the end of the plant’s life. However, this does not mean that the plant gets thrown out after it blooms; monocarpic plants will produce up to dozens of pups in its lifetime, depending on the plant, and the original plant will live on through its multiple offspring. Sometimes it will take years for the death bloom to develop and years for the plant to die after the bloom.
Drainage
[noun]
Drainage is, at minimum, a hole in the bottom of the pot. Drainage can be critical to the health of your plant. Roots need to breathe just like the leaves do. If excess water isn’t let out of the pot or the soil is compacted or too water-retentive, the roots will fail and die off. Dead tissue in wet soil invites pest breeding, bacteria growth, and root rot, which may not be visible until it’s too late. In order to add more drainage for a plant that is being overwatered, try adding more holes in the bottom or sides of the pot (like orchid pots), or adding soil amendments like pumice, lava rock, charcoal, and (for tropical plants) bark. All plants appreciate more drainage, but more drainage means that water-chugging tropical plants will need to be watered more often.
Dormant
[adjective]
Dormant is a state a plant will enter in winter when sunlight is low, in drought when water is low, or in other conditions where it cannot make enough food to support growth. During dormancy, the plant will focus on surviving, living off of the small amount of food it can make or the water it has stored. It may drop leaves or simply stop or slow its growth.
E
Epicuticular wax
[noun]
Epicuticular wax is wax found on the outer skin of all plants but can be thick enough to be visible and wipe off when you touch it. It’s most commonly seen on the bodies and leaves of succulents; extra thick to protect the water that they store in their bodies from evaporating and their skin from burning.
Epiphytic
[adjective]
Epiphytic plants are plants that use other plants and structures to support themselves, such as trees or buildings. They are specially adapted to take in water and nutrients from the air and surfaces surrounding them using aerial roots. Some epiphytic plants root into the ground and climb using their aerial roots, while some only require something to hold onto. Examples include: Epipremnum aureum “Pothos”, bromeliads, ferns, and Epiphyllum angulier “Ric Rac Cactus” (notice that genus name Epiphyllum, a group of climbing cacti, which has the same prefix as epiphytic: epi- meaning on, upon or over).
Etiolation
[noun]
Etiolation is a stretching that will happen to plants, most dramatically to succulents or high light plants, when they are reaching for light. As they grow, the space between leaves will increase and the new leaves will be thinner and longer. If your plant becomes etiolated, give it more light.
F
Family
[noun]
Family is a ranking in our taxonomic categorization of living (and dead) organisms. The scientific name of each plant does not include the family name because family is one level above genus and we refer to plants as their genus name and then species name. But knowing a plant’s family can help you understand what it is closely related to and how to take care of it.
Fenestration
[noun]
Fenestrations look like holes or cuts in the mature leaves of a plant. As the plant matures, the new leaves grow with more and more fenestrations. Plants most likely evolved to grow them so that, as the leaves get larger as the plant matures, rain, wind, and sunlight can still get through the leaves. Examples of plants that grow fenestrations include: Monstera deliciosa, Rhaphidophora tetrasperma “Mini Monstera”, and very mature Epipremnum aureum “Pothos”.
Fern
[noun]
Ferns are a type of plant that reproduce through spores instead of flowers/fruits/seeds. These spores are found on the underside of the leaves. Ferns are plants of the phylum/division (3rd highest level in the 8 level taxonomic chart for classifying plants) called Polypodiophyta.
Fibrous roots
[noun]
As opposed to taproots, fibrous roots are a system of roots that grow in a web-like, branching form without a central root. They look like a bush of roots.
G
Genus
[noun]
Genus is a ranking in our taxonomic categorization of living (and dead) organisms; the second most specific/lowest ranking. The genus is the first word in the scientific name of a plant and is capitalized. For example, the genus of a Monstera deliciosa is Monstera, and it is in the same genus as Monstera adansonii. The second word in the scientific name is the species. The plural of genus is genera (or genuses, that’s fine too).
Germination
[noun]
Germination is the transformation of a plant from a seed or a spore into a baby plant. A seed will germinate if it thinks it has found a secure spot and the right conditions, sometimes after a period of dormancy where it landed, like over winter or during a dry period before the rainy season begins. Germination does not mean the plant will be successful but the seed has fulfilled its role.
Glochid
[noun]
Glochids are the tiny hair-like spines that grow on the areoles/nodes of some cacti. Glochids may look so small that you think they’re harmless and fuzzy but some are micro-barbed so they will stick to anything, including your skin, and cause major irritation. The small size makes them hard to remove so take precautions and use duct tape to remove them from your things and yourself.
Grafting
[noun]
Grafting is a technique that combines the best parts of two plants to maximize growth. One plant is cut or wounded and the growing end of another is placed on or in the cut and secured so that the plants will grow together and become one. This is done so that the strong roots or base of the ‘rootstock’ (bottom) plant support the ‘scion’ (grafted on) plant which has a fruit or a feature that is desirable, but would not support itself or grow as quickly with its own roots. This is common with fruit trees and cacti. One of the most common examples are “Moon Cacti” which you’d likely recognize from your local Home Depot or grocery store. The colorful round cacti come in bright shades of yellow, orange, pink, and purple but have no chlorophyll and wouldn’t be able to support themselves without being grafted onto the body of a green, totem-like cactus, creating a sort of lollipop shape plant with a candy colored cactus on top.
H
Hybrid
[noun]
Hybrids are plants that are the offspring of two plants that are the same genus but different species. They are not genetically stable, meaning two hybrids cross-pollinated (bred) will not necessarily produce a hybrid similar to them (part of why ligers and zonkeys can’t make liger or zonkey kids). For this reason they don’t usually have their own species name and just go by a common name or list both species that were hybridized (such as Alocasia brisbanensis x odora “Tiny Dancer”), but if they are bred until stable then they may get a species name.
Hydrophobic
[adjective]
Hydrophobic material repels water (it’s hate not fear). It may seem counterintuitive but many soils, especially tropical or potting mixes, can be hydrophobic when completely dry. You’ll be able to identify the problem if the water runs off the surface of the soil and immediately out of the drainage hole or takes a looong time to soak in. The water should immediately soak into the soil and take a while to find its way to the bottom of the pot. To fix hydrophobic soil you can aerate it, submerge the pot and soil in water until they stop releasing air bubbles, or add more organic matter like compost, worm castings, or slow release fertilizer.
Hydroponic
[adjective]
Hydroponic simply means growing plants in water but it’s mostly used to describe flowing water systems with many plants, often for agricultural reasons. Hydroponics requires a nutrient source which could be added to the water, like a fertilizer, or could be a part of the system, like a fish tank (poop is full of nutrients!). The roots could be bare in the water or in a substrate like pumice, gravel, or LECA.
I
Internode
[noun], [adjective]
Internode means ‘between nodes’ and refers to the space between nodes on a stem, specifically stolon stems.
K
Kokedama
[noun]
Kokedama is a Japanese potting style where the root ball of the plant, along with some soil, is wrapped in moss and secured with string. “Koke” means moss and “dama” means ball. They can be hung, mounted to a piece of wood, or they can rest in a decorative saucer/vessel.
L
Lava rock
[noun]
Lava rock, similarly to pumice, is a porous rock material formed in volcanoes as gas and liquid escape cooling magma. Lava rock, also called scoria, is denser and heavier than pumice. Adding lava rock to your soil adds air flow, drainage, and minerals while avoiding compaction.
Leaf shield
[noun]
A shield will grow on new leaves of many types of plants that protects it until it is ready to unfurl. It is a cone shaped piece of leaf-like flesh that will grow with the new leaf, open up to let the leaf unfurl, and then when the leaf is fully unfurled, the shield will dry up and probably fall off.
LECA
[noun]
LECA stands for Lightweight Expanded Clay Aggregate. LECA consists of balls of porous, foam-like clay that come in multiple sizes for chunkier or finer roots. LECA is used as a substrate for growing plants in water, especially hydroponic systems.
Lithophyte
[noun]
Lithophytic plants, or lithophytes, are plants that grow on rocks. Whether on the surface of the rock (epilythic) or in cracks in or between rocks, these plants require less nutrition than a typical plant and are adapted to taking resources from the air and precipitation around them, usually using aerial roots. Many lithophytes are also epiphytes: bromeliads, carnivorous plants, ferns, orchids, moss and more.
M
Meristem cells
[noun]
Meristem cells are the cells in plants that are able to form any sort of plant tissue, like stem cells in the human body (pun sort of intended). Meristem cells are found at the nodes of stems, the areoles of cacti, at the tips of new growth, the roots, and are found up the petiole (leaf stem) and into the leaves of some plants.
Mother plant
[noun]
The mother plant is the original plant from which you are propagating. It will be genetically identical to cuttings or pups, but if you are harvesting fruit and using seeds then it may be pollinated with the DNA of another plant. A mother plant could have been propagated from a different mother plant (grandmother plant?).
Mounted
[adjective]
Mounted plants are plants that are attached to a piece of material- the best choice is unfinished wood- secured with moss and string. The best plants to mount are those that create aerial roots, such as orchids, aroids, bromeliads, and more. Their roots are meant to cling to a support structure, often trees, and they appreciate the air flow allowed by the moss.
Monocarpic plants
[noun]
Monocarpic plants, or monocarps, are plants that die after they bloom. This flower is called a death bloom and it comes from the center of the plant or main growth point, ending the growth. As it dies, which can take years, the plant will create pups off of themselves or in the ground surrounding the plant. A common example of a monocarpic plant is the Agave genus. They create towering flower stalks that grow, bloom, and die over the course of a few months, but leave several little clones in their place.
Monocotyledon
[noun]
All flowering plants are either a monocotyledon or a dicotyledon. A monocotyledon is a species of plant that has one embryo in the seed as opposed to the two found in the seed of a dicotyledon. These plants have a straight, parallel pattern of growth in the leaves and leaf veins, a specific flower and pollen structure, and typically grow a taproot. Common monocots include palm trees, plants of the Dracaena (and Sansevieria) genus, bromeliads, and orchids!
N
Native
[adjective]
Native plants are plants that existed in an area before human intervention. They are the best evolved to thrive in and support their ecosystem. It is helpful to know where a houseplant is native to so you can recreate the conditions in which that plant would thrive.
Node
[noun]
Nodes are the spots on a stem where the leaves or branches grow from. This is also where aerial roots grow on epiphytic plants, where flowers come from, and where roots come from when propagating a plant. Nodes are full of meristem cells, which allows them to make all kinds of different plant parts.
Nursery pot
[noun]
A nursery pot is the plastic pot that plants usually come in when you buy them. They can be flimsy but are typically non-recyclable (especially in Chicago) and often useful for potting a plant you want to put in a cachepot or for propagating plants.
O
Overwatering
[noun]
Overwatering means causing the roots of a plant to die and rot from too much water. As long as you have adequate drainage, overwatering has less to do with the amount of water you pour into the plant and more to do with the frequency of watering. All plants want their soil to be fully saturated with water when they are watered. If you’re using the right soil then the soil should hold onto the right amount of water for the plant. Proper drainage means the soil isn’t forced to hold onto more water than it wants. The time you wait between watering allows the roots to take in the water and breathe air through the soil before being given water again. Overwatering is when the roots drown from lack of air and die, hosting root rot and pests.
P
Parasite
[noun]
Parasitic plants, or parasites, are epiphytic plants that not only use other plants for physical support but also siphon water and nutrients from them. They used modified roots to actually get inside of the host plant and connect to its transport tissue (the xylem and phloem aka the plant’s veins) and steal the water and nutrients that it transports.
Pebble tray
[noun]
Also known as a humidity tray, a pebble tray is a saucer that is filled with water and gravel, pumice, lava rock, or another mineral substrate that allows the pot to sit above the water line. This allows the water in the saucer to evaporate, rather than soaking into the pot and soil, and create humidity around the plant. The best material for the tray part of a pebble tray saucer are non-porous, like plastic or glazed ceramic so that the water does not travel through the saucer to whatever surface the tray is sitting on. Pebble trays require frequent refilling, usually at least once a day, so it’s not the most consistent source of humidity.
Perennial
[adjective]
As opposed to annual, perennial plants are plants that will continue to grow for years, even if part of it dies back due to stress like weather or water availability. For some plants, being annual or perennial is programmed into their DNA. These annuals will produce seeds and then die, but for some, being annual or perennial has a lot to do with the climate and location. Some plants that are perennials in warmer climates are sold as annuals in places with harsh winters.
Perlite
[noun]
Perlite is an artificial version of rock/mineral substrates like lava rock and pumice. It adds air flow to your soil and retains water, releasing it when the space around it is dry, while not allowing your soil to get too compacted. Perlite is made from glass; it’s essentially glass foam. Its porousness is much finer than pumice or lava rock and it’s very light, so it can float to the top of the pot when you are watering until it absorbs the water. Perlite dust is also be dangerous to inhale, so use it while repotting outdoors.
Petiole
[noun]
The petiole is the stem-like piece of the leaf that attaches to the stem of the plant. Sometimes it looks like a stem separate from the leaf and sometimes the petiole is just a continuation of the leaf.
Photosynthesis
[noun]
Photosynthesis is the process that a plant uses to create food from sunlight so it can store the energy from the light and use it later. The plant uses chlorophyll to capture the light and the food is made from carbon dioxide and water. Oxygen is a byproduct of photosynthesis that is released out of the pores of the leaves.
Phloem
[noun]
The phloem is one of the two types of tissue in a plant that transports water and nutrients throughout the body of the plant, the other being the xylem. The phloem is responsible for transporting the products of photosynthesis (sugars and proteins) from storage to the active, growing parts of the plant. Like the xylem, the phloem is found in the wood of a tree, surrounding the xylem, or sometimes, between the spots of xylem.
Phytotoxicity
[noun]
Phytotoxicity (phyto- meaning related to plants) is any damage or deformed/slowed growth caused by an outside substance. Many substances, even beneficial ones like fertilizer, can become phytotoxic if the conditions are wrong (too hot, directly in the sun, too large an amount, too frequent of application, etc). Always read the instructions when applying anything to the leaves or soil of your plant.
Propagation
[noun]
Propagation is creation of a new, separate plant. It is a very broad term, but in the world of houseplants, propagation mostly refers to the human action of taking a piece of a plant to grow another. It depends on the plant which part of the plant needs to be separated so that it continues to grow or grows new roots/leaves. Some plants will propagate from rhizomes/corms/tubers, some will grow from just a leaf, some need a cutting of the body.
Pumice
[noun]
Pumice, similarly to lava rock, is a porous rock material formed in volcanoes as gas and liquid escape cooling magma. Pumice is lighter and more porous than lava rock, but it’s heavier and more absorbent than perlite. Pumice is what perlite wishes it was. Adding pumice to your soil adds air flow, drainage, and minerals while avoiding compaction.
Pup
[noun]
Pups, also known as plantlets, are the offspring of a plant that grows off of the mother plant, genetically identical to the mother as opposed to grown from seed which would have the DNA of the plant that fruited and the plant that pollinated the fruit. A wide variety of plants produce pups such as Aloe vera, snake plants, Pilea peperomioides, bromeliads, and more. Some pups are made through corms, tubers, bulbs, or rhizomes. Plants like Kalachoe daigremontiana “Mother of Millions” make pups on the edges of their leaves.
R
Repot
[verb]
Repotting is a little more involved than just moving a plant to a new pot and filling the gaps with soil. The best way to give plants the best success after a repot is to give the root ball a nice massage before putting it in its new home. This should remove the bulk of the old, nutrient-deficient soil and help the roots grow outwards instead of in the shape of the old pot. For more information, read “How to Repot a Plant” (coming soon).
Rhizome
[noun]
Rhizomes are the offshoot of a plant that grows beneath the ground and creates pups that sprout from the ground near the original plant, or mother plant. It is a modified stem, like a subterranean version of a stolon. Often they grow swollen and store water and nutrients, like bulbs. Plants that create rhizomes include Zamioculcas zamifolia ‘ZZ Plant’, the Sansevieria genus, some Begonia species, and ginger (the rhizome is the part we eat)!
Root-bound
[adjective]
Root-bound is what a plant can become if it has been in its pot for a long time or it is in too small of a pot. The plant’s root system will reach the walls of the pot and start to move along the wall of the pot looking for more space. When you pull the plant out of the pot, roots will be wrapping the substrate and themselves in the shape of the pot. The roots may start to poke out the drainage hole of the or out the top of the soil. A root-bound plant will soak up the water faster so you may have to water more often or the plant will act under-watered. These are good indicators that it’s time to repot your plant into a bigger pot.
Root ball
[noun]
Also called the root system, the root ball is the main chunk of roots of a plant. When repotting, mounting, or otherwise placing a plant, you want the root ball to have space to grow, but be able to reach the edges of the substrate in the pot and soak up all of the water.
Root rot
[noun]
Root rot is the bacterial infestation in roots that have been waterlogged, or overwatered, and suffocated. The dead tissue supports the bacteria and it spreads, eating the roots of the plant as the plant slowly suffers. It is often hard to catch root rot until it is already a big problem because the roots are underground, which is why drainage is so important for preventing root rot and, sometimes, diagnosing it.
Rosette
[adjective], [noun]
Rosette is an upright form many plants will grow in. Plants like Echeveria species, or upright Philodendron species grow with their leaves in an array around the stem at the center, like the petals of a rose. A plant growing in a rosette form doesn’t mean plants stay short or are wider than they are tall.
S
Saturate
[verb]
Saturating the soil or substrate that your plant is in means making sure that all of the soil has been allowed to soak up water. This is important so that none of the plant’s roots die of dehydration. But, saturating is no different from overwatering, or waterlogging, a plant if all of the excess water is not allowed to drain.
Scientific name
[noun]
The scientific name is the unique name of a plant that includes the genus and species, in that order. It can never refer to two plants but plant names can change when new information shows it was previously in the wrong genus or believed to be the same as another plant. For example, the Sansevieria genus (whose common name is ‘Snake Plants’) were reclassified as a subgenus of the genus Dracaena, so now the scientific name for Sansevieria trifasciata has a synonym of Dracaena trifasciata.
Soil
[noun]
Soil is a mixture of organic matter like plant fiber or compost and mineral or rock like pumice, lava rock, sand, or clay. The soil mixture that a plant will thrive in depends on the environment that the plant is native to. Whatever the mixture, healthy soil has air movement for gas exchange and living bacteria to help the roots process nutrients.
Soil amendment
[noun]
A soil amendment is any material/substrate that you add to your soil in order to tailor it to fit the needs of the specific plant you’re potting. Soil amendments like bark, sphagnum moss, and compost add water retention; pumice, lava rock, or LECA add aeration; compost, Plant Biotics, or other fertilizers add nutrients; there are even soil amendments like activated charcoal to prevent the growth of rot or algae.
Soilless medium
[noun]
Soilless medium is any substrate mix that doesn’t have organic ingredients like compost, bark, coco coir. It can include peat moss, which is organic, because peat and sphagnum mosses are anti-bacterial and very water-retentive, but they resist decomposing and avoid compaction. Plants are usually in soilless medium so that you can have more control over their nutrient intake whether it’s a plant that doesn’t like an abundance of nutrients like orchids, or whether it’s to avoid rot like in a hydroponic system.
Species
[noun]
Species is a ranking in the classification/taxonomy of living (and dead) organisms. The species name is the second word in the scientific name of a plant and is not capitalized. For example, the species of a Monstera deliciosa is deliciosa. Sometimes the same species name can be used to name plants in different genera that have similar features, such as Peperomia orbifolia and Calathea orbifolia which both have round, circular leaves (orb meaning circular and folia meaning leaves).
Spine
[noun]
Spines are the “spikes” or “thorns” of a cactus. They come from the areoles on a cactus and they are made of dead cells, like the nails of a cactus. Spines provide the obvious protection from people and animals and weather but they also provide shade, diffuse wind around the cactus, and sometimes help the cactus propagate itself by attaching to passersby.
Stolon
[noun]
Stolons are a type of plant stem that are classified by growing along the ground or up a support structure using aerial roots. Stolons also propagate the plant using plantlets that grow from nodes along the length of the stem. Some plants are faster growing and are called trailing because they have many nodes per stem and only one or two leaves per node like Monstera adansonii ‘Swiss Cheese Vine’. Some plants will grow much more slowly and focus on developing each plantlet so they may only have one or two per stem, like Chlorophytum comosum ‘Spider Plant’. Stolons are found on all types of plants, both tropical and arid.
Substrate
[noun]
Substrate is the material that the plant is growing in and receiving water and nutrients from. Often, this is soil, but some plants can grow in substrates like pumice, LECA, sphagnum moss, and even water.
Succulent
[noun], [adjective]
Succulent is a name or description that typically refers to a plant that has thick leaves where it stores water (examples: the Echeveria genus or the Senecio genus). However, succulent is an umbrella term for plants that store water, not just in their leaves, making them able to handle periods of drought. This includes cacti, caudiciforms, and plants that grow tubers. Some plants are considered semi-succulent if they have thicker, water-storing leaves or roots and can dry out more than most tropicals but aren’t drought tolerant like succulents.
T
Taproot
[noun]
As opposed to fibrous roots, taproots are one large center root with smaller roots attached to them. Carrots are a taproot.
Taxonomy
[noun]
Taxonomy is the way we categorize every living creature on the Tree of Life. The modern taxonomy or taxonomic chart that we use to classify all living organisms has 8 levels of organization: Domain (broadest), Kingdom, Phylum/Division, Class, Order, Family, Genus, and Species with domain being the most broad and species the most specific. We refer to organisms by their scientific name which is genus and species.
Terrestrial roots
[noun]
Terrestrial roots, as opposed to aerial roots, are roots that grow underground. Most roots are terrestrial, but we just call them roots. Aerial roots can turn into terrestrial roots if they reach the ground and realize that they have substrate to grow into.
Tropical
[adjective]
Tropical plants is an umbrella term for plants that enjoy a lot of humidity and want to maintain moisture in the soil. The amount of moisture depends on the plant (see ‘How to Water a Plant’ if you need some advice). Plants do not have to be from the tropics to be considered tropical plants. The opposite of tropical is arid.
Trailing
[adjective]
Also known as vining, climbing, or crawling, trailing is the way certain plants grow long, thin stems (called stolons) that are not stiff enough to hold up the branches. They usually also have roots (known as aerial roots until they burrow underground) along the stem at each node. Trailing plants can often be found in hanging baskets. Trailing is the opposite of upright.
Tree
[noun]
Trees are not a definitive group of plants, meaning not all trees are closely related. Many different plants from different branches (pun not intended) of plant taxonomy have evolved to grow similarly: a trunk and some sort of branches. To get specific with it, a tree is a woody plant with secondary growth, meaning it doesn’t just grow at the tips of branches, but it also grows outward from the trunk. This definition rules out plants that we typically refer to as trees, like banana “trees” (the genus Musa) or palm “trees” (the family Arecaceae).
Top dressing
[noun]
Top dressing is the name for a number of materials that are used to cover the substrate in a pot, either for aesthetic reasons or for functional ones, like getting rid of fungus gnats. The material should depend on the plant; common top dressings include sand, lava rock, bark, and gravel.
Tuber
[noun]
Tubers are a root structure that stores water and nutrients, much like bulbs or corms. They form to support the plant through changing conditions but they are also how some plants self-propagate. Tubers are able to survive dormant for long periods underground or out of soil in cool, dry conditions. Plants that create tubers include some Begonia species and potatoes.
U
Unfurl
[verb]
Unfurling is the unrolling of a new leaf. Many plants’ new leaves emerge from or separate from the latest leaf in a curled up state, sometimes with leaf shields, and once they’re ready to absorb sunlight, they unfurl.
Upright
[adjective]
As opposed to trailing plants, upright growing plants do not (usually) require support. They grow straight up and do not have roots along the stem (except for some plants like the Ficus genus that grow aerial roots when they are mature).
V
Variegation
[noun]
Variegation is any variation in the green of a plant leaf due to changes in the chlorophyll or anthocyanins. It is a very broad term but it is used most commonly to refer to mutated varieties of common plants that cause unique patterning. Variegation can be white, pink, light green, or even dark purple patterns on the leaves/body of the plant.
Variety
[noun]
Varieties are plants of the same species that have differing characteristics, like variegation, different color flowers, or different shaped leaves. Varieties that have been created through selective breeding are called cultivars.
Vermiculite
[noun]
Vermiculite is a mineral based substrate used as a soilless medium or a soil amendment. To make vermiculite different minerals, which are all in the mica family, are heated which makes the layered minerals “exfoliate”, or expand, creating space between the layers. Now porous, the mineral will absorb water and nutrients, releasing them slowly and giving roots something to cling onto, especially when used in a hydroponic setting. Adding vermiculite to your soil gives the soil more airflow and water/nutrient retention, especially if your soil is swampy or sandy
W
Waterlogged
[adjective]
Waterlogged is what a plant becomes when it doesn’t have proper drainage or it’s in too water-retentive of soil. If plants are waterlogged for too long or too often, they will get root rot.
Water retention
[noun]
Water retention is how much water a substrate holds. Organic materials like plant fibers, bark, or compost hold onto water while mineral materials like gravel and sand do not hold onto water and increase the drainage of soil. Substrates like pumice, lava rock, or LECA have water retention but still allow for lots of airflow and drains much faster than organic materials.
Wood
[noun]
Wood is a type of flesh that certain plants (referred to as woody plants) grow in the roots and stem as the plant matures. It is created from the living tissue on the outside of the plant, the cambium, which grows outward. The wood cells are tall, hollow cells with thick, rigid walls that hold the plant stable. Wood is where the xylem and phloem are located. Not all woody plants are trees.
X
Xylem
[noun]
The xylem is one of the two types of tissue in a plant that transports water and nutrients throughout the body of the plant, the other one being the phloem. The xylem is responsible for bringing water and minerals from the roots of the plant to the rest of the body. The xylem is located in the center of the trunk as a band or group of spots arranged around the center.