Ptilotrichum C. A. Meyer

54. Ptilotrichum C. A. Meyer 2

Perennial herbs or small shrubs; hairs stellate or indumentum lepidote. Sepals erecto-patent, not saccate at base; petals white to purple, entire; filaments usually not toothed or winged. Fruit a latiseptate silicula; valves flat or inflated, without a conspicuous median vein; style short; stigma capitate or emarginate. Seeds 1 or 2 in each loculus, winged or not. 1 Petals purple; stems 2-5 cm 9. purpureum 1 Petals white or rarely pink; stems 15-30 cm or more 2 Branches becoming spiny at the apex 3 Spines simple; petals abruptly contracted into claw

7. macrocarpum 3 Spines branched; petals gradually narrowed into claw

8. spinosum 2 Branches not spiny at the apex 4 Stems 25-60 cm, fragile;basalleavesobovate-spathulate

6. longicaule 4 Stems 7- 15cm, tough;basalleaveslineartooblongorobovate-

lanceolate 5 Silicula pubescent or lepidote 6 Basal leaves obovate-lanceolate; style ± equalling silicula

1. pyrenaicum 6 Basal leaves lanceolate or linear; style much shorterthan silicula 5. cyclocarpum 5 Silicula glabrous 7 Petals ± orbicular; leaves broadly spathulate 2. reverchonii 7 Petals obovate or oblong; leaves oblong or linear 8 Seeds broadly winged; infructescenceshort, dense,corymbose 4. halimifolium 8 Seeds narrowly winged; infructescence lax, elongate

9 Stock without persistent leaf-bases; silicula patent or deflexed 3. lapeyrousianum

9 Stock covered with persistent leaf-bases; silicula erectopatent 5. cyclocarpum