7 8 Flora of the Palouse Region 



1 20. TRAUTVETTERIA. 



Tall erect perennial herbs: leaves palmately-lobed, the radical 

 large and long-petioled; the cauline few, short-petioled or sessile: 

 flowers white, in corymbs: sepals 3-5, broad, concave: petals none: 

 stamens numerous: pistils numerous, i-ovuled: akenes capitate, 

 sharplj'-angled. inflated, tipped with minute styles. 



T. graildis Nutt. Sterns 30-50 cm. tall, glabrous or nearly so: leaves 

 broader than long, 8-30 cm. across, 5-9-cleft, the lobes oblong or obovate, 

 acute, incisely lobed and toothed: akenes smooth, ovate, three angled, tipped 

 with a slender recurved beak. Infrequent along streams, Thatuna Hills. 



121. RANUNCULUS. 



Annual or perennial herbs: cauline leaves alternate: flowers sol- 

 itary or corymbed: sepals usually 5, deciduous: petals as 

 many or more, conspicuous or minute, with a nectariferous pit 

 and a scale at the base of the blade: stamens numerous, occasion- 

 ally few: pistils numerous, i-ovuled: akenes capitate or spicate, 

 generally flattened, tipped with a minute or an elongated style. 



Aquatic, the immersed leaves finely divided. R. aquaTilis. 



Terrestrial, but often growing in wet places. 



Akenes hispid: annual. R. hebecarpus. 



Akenes smooth: perennials. 



Leaves all entire: creeping. R. fi v ammula. 



Leaves all entire: erect. R. alismaefolius. 



Radical leaves entire or 3-lobed at apex; cauline leaves 3-cleft. 



R. GLABERRIMUS. 

 Radical leaves palmately cleft or divided. 



Flowers very small. R. TENELLUS. 



Flowers large. R. maximus. 



R. aquatilis L. Stems 5-40 cm. long, slender, growing in water: im- 

 mersed leaves flaccid, all finely divided into filiform segments, 8-20 mm. 

 long; floating leaves 1-5, reniform or orbicular, 3-5-lobed or parted: petals 

 white, yellow at base, each bearing a naked nectariferous pit: akenes thick, 

 transversely wrinkled, the style short: receptacle hairy. 



var. trichophylluS Gray- All the leaves immersed and divided into cap- 

 illary segments. Common in ponds, both forms often associated; with the 

 drving up of the ponds, a prostrate terrestrial form sometimes occurs. 



R. hebecarpus Hook. & Am. Annual; whole plant hairy: stems slen- 

 der, mostly erect, 15-30 cm. tall: leaves 2-3 cm. broad, 3-parted, the lobes 

 incisely 3-lobed; petioles of the leaves much longer than the blades: petals 

 small, 2 mm. long, about equalling the sepals: akenes flattened, with short 

 hooked beaks, the sides roughened and covered with hooked hairs. Moist 

 copses, Wawawai. 



R. nammula var. intermedius Hook. Stems slender, creeping, rooting 

 at the joints, 15-30 cm. long: leaves narrowly-lanceolate, short-petioled, 

 acute at each end, 2-5 cm. long, shorter than the internodes: flowers small, 

 yellow, mostly solitary on the ascending tips of the stems: akene small, 

 smooth, short-beaked. Gravelly borders of small streams, infrequent. 



