Flora of the Palouse Region 79 



R. alismaefolius Geyer. Glabrous throughout, rather stout, 40-60 cm. 

 tall, branched above: radical leaves long-petioled, lanceolate or ovate, ob- 

 tuse, usually cuneate at the base, entire or obscurely denticulate, 5-10 cm. 

 long; cauline leaves narrower, mostly sessile: peduncles elongated: sepals 

 small: petals yellow, cuneate-obovate, strongly-nerved, 8 mm. long: akenes 

 turgid, smooth, short-beaked. Borders of ponds, common. 



R. glaberrimus Hook. Nearly glabrous throughout, the stems erect or 

 ascending, 5-15 cm. high: roots fascicled, elongate, fleshy: radical leaves 

 ovate, entire or crenately 3-lobed at apex, 1-3 cm. long, on petioles as long 

 or longer; cauline cuneate-obovate, deeply 3-lobed, usually sessile: petals 

 5-15, broadly obovate, .5-1 cm. long, bright yellow: akenes subglobose, 

 smooth, short-beaked, aggregated in a globose head about 1 cm. in diam- 

 eter. Common in moist places: blooming in earliest spring. 



R. tenellus Nutt. Erect, 40-60 cm. tall, glabrous or somewhat pub- 

 escent: leaves deeply 3-5-cleft, the lower cuneate-obovate, incisely 2-5- 

 toothed; petioles longer than the blades: flowers few in open cymes, long- 

 pedicelled: petals 5, very small, pale yellow: akenes much flattened, smooth, 

 each with a hooked beak, aggregated in globose heads. 



var. lyallii Robinson. More pubescent: akenes with a few hairs on each 

 face. In copses and low places, infrequent. All intergradations occur be- 

 tween the type and the variety. 



R. maximus Greene. Stout and tall, 40-80 cm. high, usually rough-pub- 

 escent with long hairs: roots fascicled, thick-fibrous: leaves pinnately 3-5- 

 divided, the divisions stalked and again 3-5-cleft or parted; ultimate seg- 

 ments cuneate-oblanceolate or obovate, incisely few-toothed; petioles of the 

 radical leaves exceeding the blades: flowers in an open cyme, long-pe- 

 duncled: sepals hairy: petals 5, bright yellow, obovate, 1.5 cm. long: akenes 

 flattened, smooth, with stout straight beaks. Common in low meadows. 



122. THALJCTRUM. 



Erect perennial herbs: leaves 2-3-ternately compound, radical 

 and cauline, the latter alternate: flowers perfect, polygamous or 

 dioecious, generally small, greenish-white, in corymbs, panicles or 

 racemes: sepals 4 or 5, petal-like or greenish, dull-colored: petals 

 none: stamens numerous: pistils 4-15, commonly few, i-ovuled: 

 akenes capitate, grooved or ribbed, or inflated. 



T. OCCidentale Gray. Dioecious: stems .5-1 m. tall: leaves ternately de- 

 compound; leaflets oblong, obovate or orbicular, incisely dentate at the apex, 

 glabrous, 1-2 cm. long: panicle loose: sepals elliptic-cuneate, greenish: fila- 

 ments very slender; anthers linear, slender-pointed: akenes 6-12, in loose 

 clusters, lanceolate, long-acuminate, 3-nerved on each side, 6-8 mm. long. 

 Moist woods and copses, not rare. 



Family 32. BKRBERIDACEAE. 



Shrubs or herbs: leaves alternate, mostly compound or divided, 

 with stipules or dilated bases: flowers perfect, the bracts, sepals, 

 petals and stamens all opposite; all the parts distinct and hypogy- 

 nous: sepals and petals usually in two rows of three: anthers 

 opening by two valves or lids hinged atthetop: pistil single; style 



