By John Green, Texas Certified Expert Gardener, Orange County, TX
Let’s begin today with a short biology review, specifically taxonomy-the branch of biology that deals with describing, identifying, nomenclature, and classifying plants based on their similarities and differences with other species that includes naming organisms, placing organisms into groups based on physical characteristics, evolution, and genetics. Systematics, another branch of biology studies the diversity of life, relationships among different organisms, and classifying organisms based on their evolutionary history, genetic similarities, and shared characteristics. Utilizing an organized, systematic approach provides us with the ability to better understand our world with its vast biodiversity. There are six distinct kingdoms: Archaebacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia.
Plants belong to the plantae kingdom and include multicellular, eukaryotic organisms (cells which contain a nucleus with other membrane-encased structures, i.e. organelles) which are typically photosynthetic, meaning they generate food by means of sunlight. This kingdom includes groups familiar to all gardeners: ferns, conifers, mosses, trees, herbs, bushes, grasses, vines, and flowering plants. The photosynthesis process captures water and carbon dioxide which are converted into oxygen and sugar (carbohydrates) both of which are required for human existence providing the primary fuel for life. This concludes today’s biology lesson!
There are numerous ways to describe plant characteristics: scientific (technical descriptors) which are arduous requiring study but are detailed and specific, whereas non-scientific (colloquial) approach is often used for ease-of-understanding. Characterizing plants using colloquial (layman’s) terms can be confusing and often misleading as the descriptors are too generic causing confusion. Informal plant characterizations often vary by region and further create more confusion.
What are the frequently used (unscientific) terms to describe plants? When speaking about plants, there are a wide variety of terms used to describe them based on different plant characteristics such as type, habit, duration, part, and other ‘general’ descriptors:
Type
Grasses – plants having slender leaves and reproduce via underground rhizomes or seeds.
Shrubs- woody plants having multiple branches, bushy, intermediate stature, and shorter
than trees.
Trees- woody, single-trunked, statuesque plants that grow into tall, multilimbed
structures.
Herbs- small plants with soft, delicate stems, usually with annual or biennial growth
cycles completed within 1 or 2 seasons.
Vegetables- are edible plants or plant parts that include roots, stems, leaves, fruit, seeds,
and flowers. Broadly classified into cool or warm-season types.
Habit
Climbers- describe plants which require a rigid support structure.
Creepers- plants that spread horizontally with weak stems, and that grow along the ground.
Vines- plants which have stems that climb or trail requiring a support structure.
Lianas- are woody vines that climb on trees or require other supports.
Succulents- similar to cacti plants that have juicy, fleshy stems which retain moisture.
Duration
Annuals- vegetation that complete a life cycle (seed to seed) in one growing season.
Biennials- plants that complete the life cycle within two seasons, the first year is vegetative growth with flowering and seeding the second.
Perennials- plants that grow for three or more years, producing flowers and seeds each year.
Evergreens- trees which do not shed leaves at the end of the growing season and retain leaves year round.
Deciduous- trees that shed leaves at the end of the growing season.
Herbaceous Perennials- are ‘non-woody’ perennial plants that die back in the winter, returning in the spring.
Woody Perennials- shrubs and trees that maintain a ‘living’ woody stem at the end of the growing season.
Parts
Roots- underground formations which anchor the plant, absorbing water, nutrients, and minerals from the soil.
Stems- are the main structural axis (vascular system) of a plant delivering water and nutrients that support leaves, flowers, and fruits.
Leaves- are flattened, green outgrowths at the end of limbs which are specialized in photosynthesis.
Flowers- are reproductive structures of flowering plants called angiosperms.
Fruits- are the mature, ripened ovary of a flowering plant that contains seeds.
Seeds- reproductive structures of flowering plants that contain the embryo and stores food for a new plant.
Rhizome- are modified plant stems that grow horizontally near or below the soil surface.
Stolon- a stem that grows along the ground surface and develops into a new plant at nodes.
Bulbs- are specialized layers of rounded underground storage organs that store water and nutrients.
Corms- are solid, swollen, underground plant stems (storage organ), like a bulb but with a distinct difference, they are one solid mass of stem tissue.
Tubers- are swollen stems or roots with “eyes” (buds), like a potato.
Other ‘general’ descriptors-
Native plant- an indigenous plant that has developed over millennia in a specific region. Our native bees, butterflies and birds are literally made from these plants. These plants are adapted to our local environmental conditions, rainfall patterns, and soil conditions. Native plants are not considered invasive plants no matter how vigorous they may become!
Non-native plant- are plants introduced by humans (intentionally or accidentally) to a new habitat where it was not previously found. Not all non-native plants are invasive, non-native plants are introduced to new places, they can reproduce or spread readily without continued human assistance.
Naturalized plant- are non-native plants not requiring human help to reproduce and maintain itself over time in non-native area. Even though their offspring reproduce and spread naturally, naturalized plants do not become native plants over time.
Exotic plant- are plants not native to our continent, i.e. plants from Europe are exotic in North America.
Translocated plant- is a plant which is not native to the portion of the continent where it is now found, such as California Poppies in New England.
Invasive exotic plant- are plants that are non-native and able to establish on many sites, grow quickly, and spread to the point of disrupting plant ecosystems. Examples of invasive exotic plants include annual ryegrass, Bermudagrass, Chinese privet, Crimson Clover, Chinese Tallow and Japanese Honeysuckle.
Noxious Weeds- any plant (invasive, non-native) designated by a Federal, State or county government as injurious to agriculture, public health, wildlife or property. Note: USDA APHIS maintains a list of federally recognized noxious weeds. It is illegal to import Federally listed noxious weeds or transport them across state lines. Some states or counties maintain lists and have passed laws regarding responsibilities for their control except for Connecticut.
Weed- a plant considered undesirable and growing where it competes with desire, cultivated plants.
Variegated- plants are characterized by leaves, stems, or even fruit exhibiting multiple colors or patterns with distinct zones of different pigments.
Mottled- plant leaf surface patterns characterized by irregular spots, blotches, or streaks of different colors or shades that create a ‘patchy’ appearance.
Glabrous- a plant surface that is smooth and lacks hairs, bristles, or glands.
Pubescent- plant surface covered in fine, soft hairs that protect the plant from insects, herbivores, and excessive sunlight, while aiding in water retention.
Glaucous- is a whitish, bluish-green, or greyish waxy coating (bloom) on leaves, stems, or fruits.
Scabrous- a plant surface that is rough to the touch due to the presence of short, stiff hairs or other small, rough projections.
This is small selection of the many terms used to describe plants based on their morphology, growth habits, life cycles, and other characteristics. Gardeners use these terms to understand, classify, and communicate the vast diversity within the plant kingdom. Sometimes it can be hard to determine exactly what category a plant is grouped into. Hopefully, these definitions will help you decide what you have in your yard and garden.
So long for now fellow gardeners! Let’s go out and grow ourselves a greener, more sustainable world, one plant at a time! Gardening questions answered: jongreene57@gmail.com.
(courtesy: micorbenotes.com).
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