CROWFOOT FAMILY 293 



verticillaris columhinna A. Gray. Woods and among bushes: B.C. — Alta. — 

 Colo. — Utah — Wash. Suhmont'^Mont. My-Jl. 



4. A. repens (Kiintze) Rydb. Plant trailing; leaves biternate, glabrous; 

 leaflets subsessile or the terminal short-stalked, broadly ovate, 3-4 cm. long, 

 abruptly short-acuminate; sepals ovate-lanceolate, about 4 cm. long, acute; 

 staminodia linear; achenes about 5 mm. long, pubescent; styles about 4 cm. long. 

 Canons: Utah — -Wyo. Suhmo7it.- Jl. 



5. A. pseudoalpina (Kimtze) Rydb. Vine climbing over bushes; leaves 

 biternate; leaflets lanceolate to ovate-lanceolate, acuminate, 2-4 cm. long, deeplj' 

 toothed or often 2-3-cleft; sepals lanceolate, 3-5 cm. long, purple or blue, rarely 

 white; staminodia linear or often lacking; achenes nearly glabrous at maturity; 

 styles 3-4 cm. long, plumose. Clematis alpina occidenlalis A. Gray. C. pseudo- 

 ntragene pseudoalpina Kuntze. Hillsides among shrubs: Colo. — Utah — N.M. 

 Submont. — Mont. Ap-Je. 



6. A. tenuiloba (A. Gray) Britton. Mostly trailing vine; leaves biternate; 

 secondary leaflets 1-3 cm. long, usually divided to near the midrib into lance- 

 olate or ovate divisions; these more or less toothed, acuminate; sepals 2.5-3.5 

 cm. long, lanceolate, acuminate, blue or purple; achenes densely pubescent; 

 styles 4-5 cm. long. Woods: S.D. — Colo. — Ariz. — Mont. Submont. — Subalp. 

 My-Jl. 



8. MYOStJRUS L. Mouse-tail. 



Small acaulescent annual mud p'ants, with fibrous roots. Leaves basal, linear 

 or filiform. Scapes 1-flowered. Sepals 5, rarely 6 or 7, long-spurred at the 

 base. Petals 5-7, narrow, greenish yellow, or wanting, the claws nectariferous 

 at the summit. Stamens 5-25. Pistils numerous, borne on a receptacle, which 

 becomes elongated and cylindric at maturity. Achenes aristate or apiculate, 

 numerous, 1-seeded, tardily dehiscent. Seeds suspended; embryo minute. 



Achenes with a flat back, only slightly carinate, and tipped with a very short appressed 

 beak. 1. ^f. minimus. 



Achenes strongly carinate on the back, tipped with a subulate, ascending beak. 

 Beak more than half as long as the achene proper; spike short and dense. 



2. A/, aristalus. 

 Beak very short; spike of the achenes long and slender. 3. M. lepturus. 



1. M. minimus L. Leaves filiform or nearly so, glabrous, 3-10 cm. long, 

 blunt; scape 3-15 cm. long; sepals oblong, about 3 mm. long; spurs 1-2 mm. long; 

 petals spatulate, long-clawed, sometimes lacking; fruiting spike 3-6 cm. long. 

 In mud and shallow water: Ont. — -Fla. — -Calif .^Wash. ; Eu. and n Africa. 

 Plain — Submonl. Ap-Je. 



2. M. aristatus Geyer. Leaves filiform to narrowly linear-oblanceolate, 

 blunt; scape 2-6 cm. long; sepals 2 mm. or less long; spurs about 1 mm. long; 

 petals often lacking; carpel-spike 3-20 mm. long. (?) M. nilidus Eastw. In 

 mud: B.C.— Mont.— Neb.— N.M.— -Calif. Plain—Mont. Ap-Jl. 



3. M. lepturus (A. Gray) Howell. Leaves filiform, 3-5 cm. long, glabrous; 

 scape 3-10 cm. long; sepals about 2 mm. long; spurs about 1 mm.; carpel-spike 

 1-4 cm. long, slender. In mud and dry ponds: B.C. — Sask. — Mont.— Calif. 

 Plain — Submont. My-Je. 



9. BATRACHIUM S. F. Gray. White Water Crowfoot. 



Perennial aquatic herbs, with floating or creeping stems. Leaves alternate, 

 palmately dissected or lobed, the submerged ones usually with filiform divisions. 

 Flowers perfect, solitary, borne opposite the leaves. Sepals and petals usually 

 5, the latter white, sometimes with a yellowish base, bearing a small pit on the 

 claw. Stamens several or numerous. Pistils many in a globular head. Achenes 

 oblique, compressed, not margined, transversely wrinkled, short-beaked or 

 almost beakless. 



Leaves all submerged and finely dissected, with linear to capillary divisions. 



Divisions of the leaves rather few, flat, 0.5-1.5 mm. wide. 1. B. Porteri. 



Divisions of the leaves very slender, filiform or capillary. 



Beak of the achenes nearly 1 ram. long. 2. B. longirostre. 



