440 RANUNCULACEAE 



1. Atragene Americana Sims. A trailing or partly climbing vine of rocky wood- 

 lands. Leaf-blades trifoliolate ; leaflets thin, ovate, acute, toothed or entire, more or less 

 deeply cordate ; petioles slender : flowers solitary, purplish blue, 5-10 cm. broad when ex- 

 panded : sepals 4, thin and translucent, strongly veined, silky along the margins and the 

 veins: petals spatulate, 12-18 mm. long: persistent styles plumose throughout. [Clematis 

 verticillaris DC.] 



In dry soil, Hudson Bay to Manitoba, North Carolina and Minnesota. Spring. PURPLE VIRGIN'S 

 BOWER. 



19. MYOSURUS L. 



Diminutive annual acaulescent herbs, with fibrous roots. Leaves basal : blades linear, 

 entire. Scapes 1-flowered, simple. Sepals 5 (rarely 6 or 7), long-spurred at the base. 

 Petals 5 (rarely 6 or 7) or wanting, when present greenish yellow, narrow ; each claw with a 

 nectariferous pit at its summit ; blades spreading. Stamens 5-25, about equalling the sepals 

 in length. Pistils numerous, borne on a central axis, which becomes greatly elongated in 

 fruit. Ovule solitary, suspended. Achenes apiculate or aristate. Embryo minute. 



1. MyoauniB minimus L. Foliage glabrous. Leaves all basal, 5-10 cm. long, nar- 

 rowly linear, blunt : scapes 2.5-15 cm. high, at length surpassing the leaves : petals 

 present, small : the elongated receptacle attaining the length of 2.5 cm. or more : achenes 

 glabrous, apiculate. 



In moist places, southern Ontario to Illinois, Kentucky and Florida. Reported from the Pacific 

 coast. Also in central Europe. Spring and summer. MOUSE-TAIL. 



20. TRAUTVETTERIA F. & M. 



Perennial herbs, with horizontal rootstocks and tall erect stems. Leaves mainly 

 basal : blades ample, palmately lobed. Flowers white, corymbosely paniculate. Sepals 

 3-5, concave, caducous. Petals wanting. Carpels numerous, 1-ovuled. Achenes capitate, 

 sharply angular, inflated, each tipped with the minute style. Embryo large. 



1. Trautvetteria Carolindnsis (Walt.) Vail. Foliage nearly glabrous, or rarely 

 pubescent. Stems stout, 4-15 dm. high, branching : basal leaves with long petioles ; 

 blades 15-30 cm. broad, deeply lobed, the lobes acute and sharply dentate : panicle ample, 

 corymb-like : flowers 6-12 mm. broad, borne in cymose clusters at the ends of the branches : 

 filaments slender, slightly widened: anthers oblong. [ Trautvetteria palmata F. & M.] 



In woods, southwestern Pennsylvania to Indiana and Missouri, but chiefly in the mountains of 

 Virginia and Kentucky to Georgia, and in western Florida. Spring and summer. FALSE BUOBANE. 



21. BATRACHIUM S. F. Gray. 



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

 blades dissected or palmately lobed, the segments of the submerged ones often filiform. Flow- 

 ers solitary, rather small, borne on peduncles opposite the leaves. Sepals and petals usu- 

 ally 5. Petals white or sometimes yellowish at the base ; each claw bearing a small pit. 

 Stamens several or numerous. Achenes oblique, compressed, not margined, often nearly 

 or quite beakless, transversely wrinkled. 



Achenes with beaks about 1 mm. long. 1. B. longirostre. 



Achenes beakless or nearly so. 



Leaf-segments 10-15 mm. long, firm : blades scarcely collapsing when withdrawn 



from the water. 2. B. trichophyllum. 



Leaf-segments 15-30 mm. long, flaccid : blades collapsing when withdrawn from 



the water. 3. B. flacndum. 



1. Batrachium longirostre (Godr. ) F. Schultz. Submerged. Foliage nearly 

 glabrous : stems very leafy, several dm. long : leaf-blades short-petioled, not flaccid, with 

 very numerous segments about 15 mm. long ; stipules broad, pubescent : pedicels 2-4 cm. 

 long : petals broadly ovate, 5-7 mm. long : head of fruit globose, 3-4 mm. in diameter. 



In ponds and streams, Ontario to Minnesota, Connecticut, Missouri and Mexico. Summer. 



2. Batrachium trichophyllum (Chaix) Bossch. Submerged. Foliage glabrous : 

 stems branching, usually 3 dm. long or longer : leaf-blades petioled, 3-5 cm. long, flac- 

 cid ; stipules short and broad, hairy : flowers white, 12-18 mm. broad, on stout peduncles 

 2.5-5 cm. long, blooming at the surface of the water: head of. fruit globose, 4-5 mm. 

 broad : receptacle hairy : achenes apiculate but beakless. [Ranunculus aquatilis var. tricho- 

 phyllus (Chaix) A. Gray.] 



In ponds and streams, Nova Scotia to British Columbia, North Carolina and California. Also in 

 Europe and Asia. Summer. A small state growing in the mud, with fleshy leaf-segments, is called B. 

 tricliophyllum caespitosum. 



