26 SPRING FLORA 



5. R. Mncounil Britton. Bristly Crowfoot. A coarse, hairy 

 plant, 1-2 ft. high, with spreading branches. Leaves 3-divided; 

 basal, or cauline and alternate. Petioles with dilated bases. 

 Flowers about % inch broad. Heads of fruit oblong. Achenes 

 with short, straight beaks. In wet places near ditches and 

 springs. June-August. 



6. BATRACHIUM. (Ranunculus in part). 



Winter annuals or perennials, growing in water or in mud 

 of ponds. Leaves filiform-dissected (in our species); petioles 

 dilated at the base. Peduncles solitary; opposite the leaves. 

 Petals white, sometimes with a yellowish base, the claw bear- 

 ing a small pit. Achenes transversely nerved. 



Leaves collapsing when taken from water. . 1. B. triehophyllum 

 Leaves not collapsing when taken from water. . 2. B. dlvaricatum 



1. B. tricophyllum (Chaix.) Bossch. (Ranunculus aquatilis 

 trichophyllus DC; B. confervoides Auct, Amer. not Fries.) 

 Common White Water Crowfoot. Stems usually a foot or 

 more long. Leaves mostly petioled, mostly more than an inch 

 long, the divisions rather remote. Petals oblong-ovate, less 

 than % inch long. Stamens 5-12. Receptacle ovoid. All but 

 the flowers submerged in water, in irrigation ditches and 

 ponds. June-August. 



2. B. divaricatum (Schrank.) Wimm. (R. circinatus Sibth.; 

 B. longirostre (Godr.) F. Schutz.) Stiff Water Crowfoot. Stems 

 usually shorter than No. 1. Leaves less than an inch long, 

 nearly sessile, dissected into capillary divisions shorter than 

 those of No. 1. Petals broadly ovate, at least y s inch long. 

 Stamens many. Receptacle conic. Achenes usually not 

 beaked (conspicuously beaked in the form known as B. 

 longirostre). 



These two species are very polymorphic, and various so- 

 called species have been Separated from them. Perhaps tha 

 most important of these is the one that has been called B. 

 flaccidum, which is intermediate in characteristics between 

 the above species. 



7. CLEMATIS. Virgin's Bower. 



Perennial herbs or woody climbers. Leaves opposite; pin- 

 nately compound or in some species simple. Sepals 4-5, 

 petaloid, valvate in the bud. Petals none, or small and transi- 

 tional into stamens. Stamens many, with adnate anthers. 

 Carpels many in a head, long-styled, ripening into long-tailed, 

 plumose achenes. 



1. C. occidentalis Hornem. (C. alpina occidentalis Gray; 

 Atragene occidentalis Hornem.) A low. half-woody climber. 

 Leaves usually 3-foliate. Leaflets slender-petioled; entire or 

 sparingly dentate; acuminate or sometimes acute. Flowers 

 large and showy. Sepals violet; acute, rather thin. Filaments 

 dilated, some of the outer ones usually petaloid. Styles per- 

 sistent and plumose in fruit. Shaded cliffs in the mountains. 

 May-July. 6,000-10,000 ft. 



