Jepson eFlora
Key to families | Table of families and genera

Key to Psorothamnus

View taxon page for Psorothamnus

1. Leaf simple, linear 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; inflorescence dense; pedicel 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; inflorescence ± open; pedicel bractlets 2

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

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

6' Leaflet narrowly elliptic to ovate or obovate, ± 1.5–3 mm wide; Mojave Desert ..... var. fremontii

5' Fruit glands few to several, large, scattered; leaves variously hairy, generally not strigose; East of Sierra Nevada to San Bernardino Mountains, Desert ..... 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


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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