CROWFOOT FAMILY 289 



numerous; filaments often clavate or dilated. Pistils few; stigmas elongate, 

 unilateral. Achenes stipitate or sessile, ribbed or nerved. 



Flowers perfect. 



Plant 2 dm. or less (rarely 3 drn.) high; achenes turgid; filaments filiform. 



1. T. alpinum. 

 Plant 3-10 dm. high; achenes flat and very oblique; filaments clavate. 



2. T. sparsiflorum. 

 Flowers dioecious or polygamous. 



Achenes turgid, thick- walled ; ribs thick and almost corky, separated by acute grooves. 

 Plants polygamous; stein-leaves subsessile, the basal ones petioled. 



Achenes, petiolules, and lower surfaces of the leaves decidedly viscid-pubes- 

 cent. 3. T. dasycarpum. 

 Achenes, petiolules, and the lower surfaces of the leaves glabrous or slightly 

 viscid-puberulent. 4. T. purpurascens. 

 Plants dioecious; all leaves petioled. 



Achenes equally acutish at both ends; leaves very thin and not strongly veined. 



5. T. dioicum. 

 Achenes more acute at the upper end than at the lower; leaves firm, strongly 



veined. 6. T. venulosum. 



Achenes more or less flattened, thin- walled; ribs not thick, separated by wide, 



shallow, rounded grooves. 

 Achenes sessile. 



Achenes more than twice as long as broad, slightly if at all oblique. 



Achenes about 4 times as long as broad, 6-8 mm. long, 1.5-2 mm. wide. 



7. T. occidentale. 

 Achenes less than 3 times as long as broad. 



Achenes 6-8 mm. long, 2.5-3.5 mm. wide. 8. T. megacarpum. 



Achenes 4-5 mm. long, 1.5-2 mm. wide. 9. T. columbianum. 



Achenes not quite twice as long as broad, decidedly oblique. 



10. T. Fendleri. 

 Achenes stipitate. 11. T. stipitatum. 



1. T. alpinum L. Stem glabrous; leaves mostly basal, 2-10 cm. long, pin- 

 nate, with the lower primary divisions ternate; leaflets cuneate-obovate to or- 

 bicular, firm, 3-10 mm. long, 3-5-lobed at the apex; inflorescence usually a 

 raceme; anthers oblong-linear; achenes few, lance-obovoid, turgid, with thick 

 ribs. T. scopulorum, T. cheilanthoides , T. subspensum, T. leiophyllum, and T. 

 duriusculum Greene. Bogs: Greenl. Newf. Colo. Calif. Alaska; n Eurasia. 

 Mont. Alp. Je-Jl. 



2. T. sparsiflorum Turcz. Stem glabrous, leafy; leaves bi- or tri-ternate, 

 the lower petioled, the uppermost sessile; leaflets thin, pulverulent-glandular 

 beneath, cordate, usually 3-cleft and the divisions 3-lobed, 1-2 cm. long; achenes 

 6-12, half rhombic with a straight back, glandular-pulverulent, with about three 

 faint ribs, 5-6 mm. long, 3-4 mm. wide. T. utahense Greene. Moist places: 

 Alaska Calif. Colo. Hudson Bay; n Asia. Submont. Mont. Je-Au. 



3. T. dasycarpum Fisch. & All. Stem tall, 5-20 dm. high; leaves 3-5 times 

 ternate; leaflets ovate or obovate, rather thick, dark green above, paler and 

 strongly veined beneath; achenes obliquely oblanceolate, about 5 mm. long and 

 2 mm. wide. Copses and meadows: Ont. la. n N.M. Sask. Plain Mont. 

 Je-Au. 



4. T. purpurascens L. Stem tall, glabrous, 3-20 dm. high; leaves 3-5 

 times ternate, glabrous or nearly so; leaflets rather thin, ovate or subcordate at 

 the base, rather light green; achenes obliquely oblanceolate, 4-5 mm. long and 

 about 2 mm. wide. Copses and woodlands: N.S. Fla. Colo. Sask. Plain 

 Submont. Je-Au. 



5. T. dioicum L. Stem 3-6 dm. high, slender; leaves 3-4 times ternate; 

 leaflets 1-3 cm. long, thin, pale beneath, rounded or sometimes cordate at the 

 base, with 3-9 rounded lobes; filaments filiform; achenes oblong, about 4 mm. 

 long. Woods: Lab. Ala. -Mo. Sask. Boreal. My-Je. 



6. T. venulosum Trelease. Stem 2-5 dm. high, glabrous; leaves 3-4 times 

 ternate; leaflets rounded in outline, 5-15 mm. long, strongly veined, 3-5-lobed 

 and crenate, bluish green, paler beneath; panicle narrow and dense; filaments 

 filiform; achenes about 5 mm. long, oblong. T. campestre Greene. Open 

 mountain woods: Man. -Colo. 'Utah. .Plain -Mont. Je-Au. 



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