Botanical Vocabulary You Actually Need

Field identification uses a specific vocabulary. The full botanical vocabulary is enormous; most of it you don't need. This lesson covers the 30-40 terms that do real work.

Habit terms — overall plant form

**Herb / herbaceous.** A non-woody plant. Dies back to the ground each year (perennial herbs) or completes its life cycle in one year (annual herbs).

**Shrub.** A woody plant under 4-5 meters (varies by definition), often with multiple stems from the ground.

**Tree.** A larger woody plant with typically a single main trunk.

**Vine / climber.** A plant that climbs other vegetation or structures for support.

Stem terms

**Round stem.** Stem cross-section is roughly circular. Most plants.

**Square stem.** Stem cross-section is distinctly four-sided. A diagnostic feature of most members of the mint family (Lamiaceae).

**Hollow stem.** Stem is hollow rather than solid. Common in many Apiaceae (carrot family) members.

**Solid stem.** Stem is solid throughout. Most other plants.

**Erect.** Stems grow upright.

**Decumbent / sprawling.** Stems grow along the ground, sometimes turning up at the tips.

Leaf arrangement on the stem

**Opposite.** Two leaves attached at the same level on opposite sides of the stem. Characteristic of mints (Lamiaceae) and several other families.

**Alternate.** Single leaves attached at different levels, alternating sides as you move up the stem. Most plants.

**Whorled.** Three or more leaves attached at the same level around the stem. Some species (like cleavers, Galium) have whorled leaves.

**Basal.** Leaves arising from the base of the plant, not from the upper stem.

**Rosette.** A circle of leaves at the base of the plant, often pressed close to the ground.

Leaf shape and edge

**Simple.** Leaf is one piece, not divided.

**Compound.** Leaf is divided into separate leaflets. Subtypes: pinnately compound (leaflets arranged along a central axis like a feather), palmately compound (leaflets arranged like fingers from a central point), bipinnately compound (leaflets themselves further divided).

**Entire.** Leaf edge is smooth, no teeth.

**Toothed.** Leaf edge has small teeth (serrate, dentate, crenate are subtypes).

**Lobed.** Leaf edge has rounded or pointed indentations (lobes) but is not fully divided.

**Divided.** Leaf is deeply cut, possibly to the midrib, but technically not compound (the divisions don't have their own stems).

Flower structure

**Petals.** The colored part of the flower (usually).

**Sepals.** The often-green outer parts surrounding the petals when the flower is in bud, sometimes visible after the flower opens.

**Calyx.** The collective term for all sepals.

**Corolla.** The collective term for all petals.

**Stamens.** The male reproductive parts; produce pollen.

**Pistil.** The female reproductive part; receives pollen and develops into the fruit.

**Inflorescence.** The arrangement of flowers on the plant. Specific types:

- **Spike.** Many flowers on a long stem, no individual flower stems. - **Raceme.** Many flowers on a long stem, each flower with its own short stem. - **Cyme.** A branched, flat-topped or rounded arrangement with the oldest flower in the center. - **Umbel.** Flower stems radiating from a single point, like spokes of an umbrella. Characteristic of Apiaceae. - **Head / capitulum.** Many tiny flowers crowded into a single head that looks like one flower. Characteristic of Asteraceae.

Flower symmetry

**Radial / actinomorphic.** Flower has multiple planes of symmetry; can be divided into equal halves through more than one axis. Most flowers.

**Bilateral / zygomorphic.** Flower has only one plane of symmetry; can only be divided into equal halves through one specific axis. Common in some families (Lamiaceae, Fabaceae, orchids).

Specific terms by family

**Composite head.** The flower head of an Asteraceae plant, made of many tiny flowers. Subdivided into: - Ray flowers (the "petals" of a daisy, which are actually each a small flower) - Disc flowers (the central yellow part of a daisy, made of many tiny tubular flowers)

**Two-lipped flower.** A bilaterally symmetric flower with upper and lower "lips." Characteristic of Lamiaceae.

**Pea flower / papilionaceous flower.** The distinctive flower of Fabaceae plants, with a "banner" (top petal), two "wings" (side petals), and a "keel" (two fused bottom petals).

**Cruciform / cross-shaped flower.** A flower with four petals arranged in a cross. Characteristic of Brassicaceae.

Fruit terms

**Achene.** A small, dry, single-seeded fruit. Each "seed" in a sunflower head is technically an achene.

**Berry.** A fleshy fruit with multiple seeds.

**Capsule.** A dry fruit that opens to release seeds.

**Drupe.** A fleshy fruit with a single hard pit (cherry, peach).

**Pod / legume.** The fruit of Fabaceae plants — a dry case enclosing seeds, splitting along two seams.

**Silique.** A specific type of pod found in Brassicaceae; long and narrow.

Roots and underground

**Taproot.** A single dominant root growing straight down (carrot, dandelion).

**Fibrous roots.** Many small roots of similar size (most grasses).

**Rhizome.** A horizontal underground stem (ginger root, iris).

**Tuber.** A swollen underground storage organ (potato).

**Bulb.** A swollen underground bud with fleshy scales (onion).

**Corm.** A swollen underground stem base (gladiolus, crocus).

Plant aromatics and textures

**Aromatic.** Releases noticeable scent when crushed.

**Pungent.** Strong-smelling, often with peppery or bitter notes.

**Glaucous.** Covered with a waxy bloom, often blue-gray.

**Pubescent / hairy.** Covered in small hairs.

**Glabrous.** Smooth, hairless.

How to use this vocabulary

For each plant you encounter, observe:

1. Overall habit (herb, shrub, tree, vine) 2. Stem (shape, hollow or solid, surface texture) 3. Leaf arrangement (opposite, alternate, whorled, basal) 4. Leaf shape and edge 5. Flower structure (radial or bilateral, count of petals, color) 6. Inflorescence type (spike, umbel, head, etc.) 7. Specific diagnostic features (compound flower head? square stem? umbel?)

These observations narrow the family possibilities dramatically. Often a few observations identify the family.

Practice exercise

Find a plant in your area (a garden plant or wildflower). Apply the vocabulary above. Write down what you observe.

Example: "A 30-cm herb. Stem is square in cross-section, hairy. Leaves are opposite, simple, toothed. Flowers are small, bilaterally symmetric, two-lipped, pale purple, arranged in dense clusters at the leaf axils."

This description points strongly to the mint family (Lamiaceae). The square stem and two-lipped flowers are diagnostic.

What to carry forward

This week, practice the vocabulary on five plants near you. Use the observation format above. The discipline is what builds skill.

Next lesson, the mint family.