80 Phytologia (Aug 2004) 86(2) 



14. Stiffly erect shrublets 30-100 cm high; leaves 

 and stems with appressed hairs, or if erect then 

 numerous and very short, superficially strigose; Jal W. cronquistii 



15(13). Hairs on achenes mostly 0.1-0.2 mm long; 



Col, Mic, Gue W. strigosa 



15. Hairs on achenes mostly 0.2-0.5 mm long; 



Nay, Jal, Zac, Agu W. rosei 



16(1). Stems prostrate or trailing, rooting at the nodes, 



forming loose, but copious ground-cover; leaves, at 



least some of them, neatly 3-lobed W. trilobata 



16. Stems erect, not normally rooting at the 



nodes; leaves not neatly 3-lobed (17) 



17. Erect to recumbent herbs or shrublets, not 



normally rhizomatous; style branches gradually 



acuminate (19) 



17. Stiffly erect, rhizomatous, coarsely hispid herbs 



to 1 m high, forming clumps in wet meadows; style 



branches abruptly apiculate; Nay, Jal (18) 



18. Leaves sessile, the blades cordate or subcordate 



at base W. cordiformis 



18. Leaves with winged petioles, the blades otherwise 

 W. simsioides 



19(17). Leaves with hairs predominently alike, if of two 

 kinds then the finer hairs not uncinate (23) 



19. Leaves with two kinds of hairs on the 

 undersurface, a longer group of straight hairs and 

 below these at least a few uncinate or recurved hairs (20) 



20. Stems suffruticose, stiffly erect, to 1.5 m high, 

 sparsely branched; achenes of the ray and disk 

 similar, unwinged, or rarely the ray achenes 

 winged; Nue, Tarn, San, (Gulf Slopes) W. ayerscottiana 



