Key to Trichostema

View taxon page for Trichostema

(For a list of species in Trichostema, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Shrub, < 1.5 m

2. Corolla tube 9–14 mm; inflorescence hairs 2–3 mm, obscuring 

pedicel 

Stalk of an individual flower in an inflorescence, or the corresponding structure in fruit.

..... T. lanatum

2' Corolla tube 4–7 mm; inflorescence hairs 1–2 mm, not obscuring pedicel ..... T. parishii

1' Annual, < 1 m

3. Petiole distinct, 5–15 mm

4. Corolla tube 4–8 mm, 

exserted 

Protruding out of surrounding structure(s) (e.g., stamens exserted from corolla).

, lower lip 4–7 mm ..... T. laxum

4' Corolla tube 1.5–3 mm, 

included 

Not protruding out of surrounding structure(s) (e.g., stamens included in corolla).

, lower lip 2–3 mm ..... T. simulatum

3' Petiole indistinct or < 5 mm

5. Corolla tube curved abruptly upward near throat; stamens 5–20 mm

6. Stamens 5–9 mm ..... T. ruygtii

6' Stamens 11–20 mm

7. Leaf 

blade 

Expanded portion of a leaf, petal, or other structure, generally flat but sometimes rolled, cylindric, wavy, or cupped.

2–7 cm, 

lanceolate 

Narrowly elongate, widest in the basal half, often tapered to an acute tip.

to narrowly 

ovate 

Egg-shaped (i.e., widest below the middle) in two dimensions (i.e., in one plane), as a leaf.

, length > 3 × width; corolla tube 5–10 mm ..... T. lanceolatum

7' Leaf blade 1–2 cm, ovate, length < 2 × width; corolla tube 2.5–5.5 mm ..... T. ovatum

5' Corolla tube curved gradually upward; stamens 2–6 mm

8. Stem, 

leaf 

Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets).

hairs curled to 

appressed 

Parallel or nearly parallel to and often in contact with surface of origin; used to describe the disposition of hairs, leaves, pedicels, etc.

; stamens 2–3 mm, ± included to ± exserted ..... T. micranthum

8' Stem, leaf hairs straight, generally 

spreading 

Oriented more or less perpendicularly to the axis of attachment; often, more or less horizontal.

; stamens 3–6 mm, exserted

9. Calyx 

lobes 

1. A major expansion or bulge, such as on the margin of a leaf, sepal, or petal, or on the surface of an ovary. 2. The free tips of otherwise fused structures, such as sepals or petals; larger than teeth.

< 2 × tube; calyx tube > mature nutlets; mature calyx generally red-tinged ..... T. rubisepalum

9' Calyx lobes > 2 × tube; calyx tube < mature nutlets; mature calyx green

10. Leaf blade widely 

elliptic 

In the shape of a flattened circle or ellipse; wider than linear

, length generally < 4 × width; calyx lobes generally widest above base ..... T. oblongum

10' Leaf blade elliptic, length generally > 4 × width; calyx lobes widest at base ..... T. austromontanum

11. Leaf <= 

internode 

Segment of an axis (generally a stem) between successive positions (nodes) from which one or more structures (especially leaves, buds, branches, or flowers) arise.

above ..... subsp. austromontanum

11' Leaf >> internode above ..... subsp. compactum

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Citation for the whole project: Jepson Flora Project (eds.) . Jepson eFlora, https://ucjeps.berkeley.edu/eflora/ [accessed on ]

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