198 RANUNCULACEAE (BUTTERCUP FAMILY) 



the tails 3-4 cm. in length. [C. Bakeri Greene, Pitt. 4: 147. 1900; C. Jonesii 

 (Kuntze) Rydb. 1. c. 153.] Colorado, northward and westward to Washington. 



4. Clematis Scottii Porter, Fl. Col. 1. 1874. Near the two preceding: 

 leaves large, with some or all the divisions 3-5-parted or 3-5-f oliolate ; lobes 

 or leaflets oblong or ovate-lanceolate; some upper leaves with distinctly 

 tortuous petiolules, as if for clasping a support. Southern Colorado and New 

 Mexico. 



5. Clematis ligusticifolia Nutt. T. & G. Fl. N. A. 1: 9. 1838. Nearly gla- 

 brous: stem more or less woody, often very long, climbing by the tortuous 

 grasping, petiolules: leaves pinnate and ternate, mostly 5-f oliolate; the leaflets 

 oblong, acute, often somewhat lanceolate-cuneate, incisely toothed and trifid: 

 flowerS white, in paniculate corymbs, dioecious: sepals thin, equaling the sta- 

 mens. From New Mexico to the Saskatchewan and Oregon, and also in Cali- 

 fornia; climbing over bushes and producing a great abundance of white flowers. 



6. Clematis occidentalis Homem.* Hort. Hafn. 520. 1813. Leaves simply 

 3-f oliolate, slender-petioled ; leaflets slender-petiolulate, ovate mostly acumi- 

 nate, entire or sparingly dentate: sepals violet, 3-5 cm. long, oblong, acute 

 or acutish: usually some of the outer stamens sterile, with enlarged spatulate 

 petaloid filaments. C. verticillaris. Colorado to California and north into 

 British America. 



7. Clematis pseudoalpina (Kuntze) A. Nels. Stems very short, trailing, 

 hardly if at all climbing: leaves biternate; the divisions lanceolate or ovate- 

 lanceolate, acute, pinnately 3-7-toothed, lobed or cleft: sepals lanceolate, 

 acute, thin, purplish-blue or rarely white: petaloid filaments (staminodia) all 

 linear, more or less antheriferous, scarcely exceeding the other stamens: 

 achenes pubescent or glabrous, with long plumose tails. C. alpina occiden- 

 talis. (Atragene repens. Rydb. 1. c.) New Mexico to Utah and Wyoming. 



7a. Clematis pseudoalpina tenuiloba (Gray) A. Nels. Differs from the 

 preceding but little: stems even shorter: leaflets more deeply incised and the 

 lobes narrow, often lance-linear. [Atragene tenuiloba (Gray) Brit, in Bull. 

 Herb. Boiss. 3: 206. 1895.] Colorado and Utah to Dakota and Montana. 



10. MYOSURUS L. MOUSETAIL 



Very small annual herbs, with a tuft of linear or spatulate entire radical 

 leaves, and solitary flowers on simple scapes. Sepals 5, spurred at base. 

 Petals 5, linear, on a slender claw with a pit at its summit. Stamens 5-20. 

 The long slender spike of achenes and linear radical leaves give the plant the 

 appearance of a diminutive plantain. 



1. Myosurus apetalus Gay, Hist. Chil. Bot. 1:31. 1845. Scapes 3-5 cm. 

 high, usually spreading, but little surpassing the linear leaves: petals often 

 wanting: spike of achenes 6-20 mm. long, ovoid-oblong and more or less 

 squarrose, or cylindrical: achenes oblong, thin- walled, with narrow, promi- 

 nently carinate back' prolonged into a spreading or ascending beak: achene ob- 

 long. Wet saline places; western N. America; also in Chile. 



11. BATRACHIUM S. F. Gray. WATER CROWFOOT 



Aquatic or subaquatic perennials or winter annuals, with filiform-dissected 

 submersed leaves and sometimes also a few dilated emersed ones; petioles 

 with dilated stipular base. Peduncles solitary, opposite the leaves. Petals 

 white, with a naked nectariferous pit upon the yellow base. Achenes margin- 

 less and transversely rugose. Ranunculus in part. 



Achenes short-beaked , 1. B. longirostre. 



Achenes beakless. 



* See discussion of this and the following species, under Atragene, by Dr. P A Rvdberjr 

 Bull. Torr. Bot. Club 29: 155-157. 1902. gt 



