RANUALULACEAE. 423 



1. Atragene Americana Sims. Purple Virgin's Bower. (I. F. f. 1592.) 



Leaves tnfoliolate; leaflets thin, ovate, acute, toothed or entire; petioles slender* 

 flowers purplish blue, 5-10 cm. broad; sepals 4, thin and translucent, strongly 

 veined, silky along the margins and the veins; petals spatulate, 12-18 mm. long; 

 persistent styles, plumose throughout. Hudson Bay to Manitoba, Conn., Va. and 

 Minn. May-June. [Clematis verticillaris DC.] 



20. MYOSURUS L. 



Diminutive annual herbs, with fibrous roots, basal linear entire leaves and 1- 

 flowered scapes; sepals 5 (rarely 6-7), long-spurred at the base. Petals the same 

 number or none, when present greenish-yellow, narrow, the claw bearing a nectar- 

 iferous pit at the summit, the limb spreading. Stamens 5-25, about equalling the 

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

 in fruit Ovule 1, suspended. Achenes apiculate or aristate. [Greek, mouse-tail.] 

 A genus of insignificant plants of local but wide geographic distribution, consisting 

 of the species here described and 4 others found in western America and Australia. 



1. Myosurus minimus L. Mouse-tail. (I. F. f. 1593.) Low, glabrous, 

 2-15 cm. high, the scape at length surpassing the leaves and the elongated recepta- 

 cle attaining the length of 3 cm. or more. Leaves 5-10 cm. long, blunt; petals 

 small; achenes glabrous, apiculate. In moist places, southern Ont. to Neb., Kans. 

 and Fla. Reported from the Pacific Coast. Also in central Europe. April-July. 



21. TRAUTVETTERIA F. & M. 



Tall erect perennial herbs, with large palmately-lobed leaves, those of the stem 

 distant. Sepals 3-5, concave, caducous. Petals none. Carpels 00 , i-ovuled. 

 Achenes capitate, sharply angular, inflated, tipped with the minute styles. Em- 

 bryo large. Flowers small, white, corymbosely paniculate. [In honor of Prof. 

 Trautvetter, a Russian botanist.] A genus of two species in N. Am. and one in 

 eastern Asia. 



1. Trautvetteria Carolinensis (Walt.) Vail. False Bugbane. (I. F. f. 

 1594.) Stout, 6-10 dm. high, branching, nearly glabrous, except the lower sur- 

 faces of the leaves. Basal leaves long-petioled, 15-20 cm. broad, 10-12 cm. long, 

 deeply lobed, the lobes acute and sharply dentate; panicle ample, the flowers 

 6-12 mm. broad, borne in cymose clusters at the ends of its branches; filaments 

 slender, slightly widened; anthers oblong. Southwestern Penn., south to Fla., 

 west to Ind. and Mo. June-July. [T. palmata F. & M.] 



22. RANUNCULUS L. 

 Herbs, with alternate simple entire-lobed or divided or dissected leaves, and 

 yellow white or red flowers. Sepals mostly 5, deciduous. Petals equal in number 

 or more, conspicuous or minute, provided with a nectariferous pit and a scale at 

 the base of the blade. Carpels 00 , i-ovuled. Achenes capitate or spicate, gener- 

 ally flattened, tipped with a minute or an elongated style. [Latin for a small frog, 

 in allusion to the marsh habitat of many species.] Some 200 species, widely distrib- 

 uted in the temperate and cool regions of both hemispheres and on mountain tops 

 in the tropics. In addition to those here described, about 50 others inhabit the 

 western and northwestern parts of the continent. 



+ Aquatic or creeping mud plants with palmately lobed, divided or dissected leaves. 

 Leaves orbicular, palmately divided. 



Achenes marginless, flowers 7-14 mm. broad. 1. R. Purshii. 



Achenes callous-margined. 



Flowers 15-30 mm. broad; leaves mostly finely dissected. 2. R. delphinifolius. 

 Flowers 6-10 mm. broad ; leaves mostly thrice 3-cleft. 3. R. Missouriensis. 

 Leaves 3-lobed or 3-cleft, cuneate at the base. 4. R. hyperboreus. 



tt Scapose plant from a filiform rootstock; leaves reniform, 3-parted. 



5. R. Lapponicus. 

 ■*■*■■*■ Plants of swamps or muddy shores: leaves entire or denticulate. 

 Annuals : achenes beakless ; tipped with the persistent style-base. 



Petals 2-4 mm. long; stamens few, 1-10. 6. R. pusillus. 



Petals 4-6 mm. long; stamens numerous. 7. R. oblongifolius. 



Perennials, rooting from the nodes : achenes beaked. 



Stems trailing; achenes minutely beaked. 8. R. reptans. 



Stems ascending or erect ; achenes subulate-beaked. 9. R. cbtusiusculus. 



