Key to Psorothamnus

View taxon page for Psorothamnus

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

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

1. Leaf 

simple 

Composed of a single part; undivided; unbranched.

, 

linear 

Elongate, with nearly parallel sides; narrower than elliptic or oblong.

or oblanceolate (or leaflets 2–3)

2. Leaves persistent; inflorescence axis not ending as thorn ..... P. schottii

2' Leaves deciduous by early summer; inflorescence axis ending as thorn ..... P. spinosus

1' Leaves odd-1-pinnate or some simple

3. Fruit 2–4.5 mm, 

included 

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

; inflorescence dense; 

pedicel 

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

 bractlets 0

4. Terminal leaflets > lateral or not; glands of twigs << 0.5 mm wide ..... P. emoryi

4' Terminal leaflets ± = lateral; glands of twigs ± 0.5 mm wide ..... P. polydenius

3' Fruit 7–10 mm, 

exserted 

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

; inflorescence ± open; pedicel bractlets 2

5. Fruit glands many, small, in longitudinal lines especially distally; leaves generally silvery-strigose; DMoj, e DSon, ..... P. fremontii

6. Leaflet linear, < ± 1 mm wide; e DSon ..... var. attenuatus

6' Leaflet narrowly 

elliptic 

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

to 

ovate 

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

or obovate, ± 1.5–3 mm wide; DMoj ..... var. fremontii

5' Fruit glands few to several, large, scattered; leaves variously hairy, generally not 

strigose 

With stiff, straight, sharp, appressed hairs.

; SNE to SnBr, D ..... P. arborescens

7. Leaflets generally continuous with axis, silky-hairy ..... var. simplicifolius

7' Leaflets generally (or at least some) jointed to axis, glabrous to hairy, including silky-hairy or not

8. Calyx 7–9 mm, sparsely to densely hairy ..... var. arborescens

8' Calyx 5–7 mm, hairs 0 or sparse ..... var. minutifolius

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