Plant Taxonomy and Field Identification
The universal language of plants — from scientific names to field identification
Chapter 6: Reading Botanical Descriptions
Why this matters: Botanical descriptions are how scientists formally document a plant. Being able to read them lets you verify identifications, understand herbarium records, and use technical floras confidently. Once you know the structure of a description, they become readable in minutes rather than intimidating.
6.1 Structure of a Botanical Description
A formal botanical description follows a consistent order:
STANDARD DESCRIPTION ORDER:
1. HABIT (overall growth form)
Annual/perennial/biennial herb, shrub, tree, vine
Height range
2. ROOT/STEM
Root type, stem characteristics
3. LEAVES
Arrangement, complexity, shape, size, margin,
surface texture, petiole, stipules
4. INFLORESCENCE
Type, position, size
5. FLOWERS
Calyx (sepals), corolla (petals), androecium (stamens),
gynoecium (pistil), ovary position
6. FRUIT
Type, size, color at maturity
7. SEEDS
Number, size, color, surface
8. PHENOLOGY
Flowering and fruiting time
9. HABITAT AND RANGE
Where it grows, geographic distribution
10. NOTES
Taxonomy notes, similar species, uses6.2 Sample Description — Translated
ORIGINAL BOTANICAL DESCRIPTION
From: 6.2 Sample Description — Translated
Image file: ../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig01.png
Save image as ../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig01.png in this folder, then replace this block with:<figure><img src="../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig01.png" alt="ORIGINAL BOTANICAL DESCRIPTION"></figure>
6.3 Abbreviations Common in Botanical Literature
MEASUREMENT:
mm = millimeter
cm = centimeter
m = meter
ca. = approximately (circa)
c. = approximately
diam. = diameter
GENERAL:
sp. = species (singular)
spp. = species (plural)
var. = variety
subsp. = subspecies
f. = forma
cf. = compare with (uncertain ID)
sensu = in the sense of (which author's interpretation)
syn. = synonym
incl. = including
excl. = excluding
GEOGRAPHIC:
n., s., e., w. = north, south, east, west
c. = central (in geographic context)
AUTHOR ABBREVIATIONS (common Texas botanists):
Torr. = John Torrey
A.Gray = Asa Gray
Engelm. = George Engelmann
S.Watson = Sereno Watson
L. = Carl Linnaeus
Michx. = André Michaux
Nutt. = Thomas Nuttall
DC. = Augustin Pyramus de CandolleChapter Summary
BOTANICAL DESCRIPTIONS follow consistent order
From: Chapter Summary
Image file: ../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig02.png
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1. Botanical descriptions use standardized terminology to precisely describe plants.
2. The word "glabrous" means covered in soft hairs.
3. "Pubescent" means hairy or downy.
4. "Dentate" describes a leaf margin with large teeth pointing outward.
5. "Serrate" describes a leaf margin with fine forward-pointing teeth.
6. "Entire" describes a smooth uncut leaf margin.
7. "Ovate" means egg-shaped, wider below the middle.
8. "Lanceolate" means lance-shaped — much longer than wide, widest near base.
9. "Obovate" means egg-shaped but wider above the middle.
10. "Cordate" means heart-shaped, with a notch at the base.
11. "Decurrent" means the leaf base runs down the stem as a wing.
12. "Sessile" means lacking a stalk — attached directly.
13. "Petiolate" means having a petiole (leaf stalk).
14. "Axillary" means arising from the axil (angle between leaf and stem).
15. "Terminal" means at the end of a branch or stem.
16. "Glaucous" means covered with a bluish-white waxy bloom.
17. "Tomentose" means densely woolly or matted-hairy.
18. "Acuminate" means gradually tapering to a long point.
19. "Truncate" means appearing cut straight across at the tip or base.
20. "Revolute" means with margins rolled toward the lower surface.
1. What is the purpose of standardized botanical terminology?
2. Describe the difference between "glabrous," "pubescent," and "tomentose."
3. What does "petiolate" vs "sessile" mean for leaves?
4. Describe four leaf shapes using correct botanical terms.
5. What is the difference between "serrate" and "dentate" margins?
6. What does "decurrent" mean and on which types of plants is it common?
7. What does "axillary" vs "terminal" mean for flowers or buds?
8. Describe the meaning of "cordate," "truncate," and "cuneate" leaf bases.
9. What does "glaucous" mean and what causes it on leaf surfaces?
10. Why is learning botanical vocabulary worth the effort?
1. "Lacking a stalk, attached directly to the stem" is described as .
2. A leaf that is much longer than wide, widest near the base, tapering to both ends is .
3. A leaf margin with small sharp forward-pointing teeth is described as .
4. A leaf with no hairs whatsoever is called .
5. Densely covered in woolly matted hair is described as .
6. A leaf or stem covered with bluish-white waxy coating is .
7. Heart-shaped, with an indentation at the base is .
8. The leaf base running down the stem as a flange or wing is .
9. A leaf tapering to a sharp point at the tip is .
Complete in the field. Check each off as you go.
1. Botanical Vocab Flash Cards: Create cards for 20 botanical terms using a botanical illustration book or flora. Test yourself on both the term→meaning and meaning→term.
2. Description Practice: Choose 3 plants and write a formal botanical description of each using proper terminology. Focus on leaf shape, margin, surface texture, arrangement, and stem features.
3. Flora Reading: Find a published flora description of a plant you know well (use the USDA PLANTS database). Identify every botanical term used. Look up any you don't know.
4. Comparison Exercise: Place three similar leaves side by side. Write a description that distinguishes them from each other using botanical terms. Can someone else identify which is which from your description?
5. Illustration and Labeling: Draw a leaf diagram and label: blade, petiole, midrib, lateral veins, margin, base, and tip. Use the correct botanical terms for the shape, margin, and surface of the leaf.
Practice Exercises
- A description says "leaves sessile, amplexicaul." What does this mean in plain language?
- What does "glabrous" mean? What is its opposite?
- A description says "achene 3 mm, crowned with pappus of 10 plumose bristles." What family is this almost certainly from?
Next Chapter → Lookalikes and How to Distinguish Them
Connections to Other Topics
→ C02 Ch03: Vegetative Identification — applying these terms
From: Connections to Other Topics
Image file: ../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig03.png
Save image as ../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig03.png in this folder, then replace this block with:<figure><img src="../../../images/s01-foundation/c02-plant-taxonomy/ch06/c02-plant-taxonomy_ch06_botanical_descriptions_fig03.png" alt="→ C02 Ch03: Vegetative Identification — applying these terms"></figure>