KANUNCULACEAE 445 



stem-leaves sessile or nearly so ; blades deeply cleft into linear-oblong obtuse segments : 

 corolla yellow, 2-2.5 cm. broad : petals much exceeding the reflexed sepals in length : 

 head of fruit oblong, 4-6 mm. thick : achenes fiat, strongly margined, short-beaked, pro- 

 vided with a series of small tubercles or papillae which become more prominent in drying, 

 or rarely nearly smooth. 



In ballast grounds and waste places, New Brunswick to New York, Virginia and Georgia. Adven- 

 tive from Europe. Summer. 



22. Ranunculus parviflorus L. Foliage villous. Stems slender, difluse, branching 

 from the base, 1.5-3 dm. high : basal leaves with long petioles ; blades reniform or cordate- 

 orbicular, 2.5 cm. broad or less, 3-cleft, the lobes broadly oval, obtuse, and toothed ; upper 

 leaves with short petioles, or blades nearly sessile, 3-5-parted into linear-oblong lobes : 

 corolla yellow, 2-4 mm. wide : petals not longer than the sepals : head of fruit globose, 4 

 mm. broad : achenes flat, margined, densely papillose, 3 mm. long, each tipped with a 

 sharp beak of about one-fourth its length. 



In waste places, Maryland and eastern Virginia to Florida, Arkansas and Texas, and in ballast 

 grounds about the nortiiern seaports. Naturalized from Europe. Also naturalized in Bermuda. 

 Summer. 



23. Ranunculus muricatus L. Foliage glabrous or sparingly pubescent. Stems 



branched from the base, 3-G dm. high. Lower and basal leaves with long broad petioles ; 



blades reniform or cordate-orbicular, 2.5-5 cm. wide, 3-lobed, cleft or crenate ; upper 



leaves with 3-divided cuneate short-petioled or sessile blades : corolla light yellow, 6-10 



mm. wide : petals exceeding the sepals in length : head of fruit globular, 10-12 mm. Avide : 



achenes flat, densely muricate and spiny on the sides, 4 mm. long, each tipped with a 



stout slightly curved beak of one-half its length. 



In waste places, eastern Virginia to Florida and Louisiana ; naturalized or fugitive from Europe. 

 Also on the Pacific Coast. Native also in Asia and naturalized in tropical America. Summer. 



24. ADONIS L. 



Annual or perennial herbs, with rather succulent tissues and erect stems. Leaves 

 alternate : blades pinnately dissected into numerous linear segments. Flowers yellow or 

 red, solitary, terminal. Petals 5-16, conspicuous. Carpels numerous, each with 1 ovule. 

 Achenes capitate or spicate, tipped with the persistent styles. 



1. Adonis dnnua L. Annual, glabrous. Stems erect, 2-6 dm. tall, branched : 

 leaves several ; blades finely dissected, 2-5 cm. long, the lower petioled, the upper sessile, the 

 segments narrow, acute, toothed or incised : flowers orange or red, 18-36 mm. broad, siout- 

 peduncled : sepals glabrous, deciduous : petals obovate or cuneate, darker at the base than 

 above : achenes 3-5 mm. long, crowded in a cylindric head 1-2 cm. long. [A. autumnalis L.] 



In waste places, widely cultivated and spontaneous in the eastern United States. 



25. THALICTRUM L. 



Perennial herbs, with erect or decumbent stems. Leaves alternate : blades ternately 

 decompound, the segments entire, toothed or lobed : petioles with dilated bases. Flowers 

 perfect, polygamous or dioecious, generally small, in panicles or racemes. Sepals greenish 

 white, 4 or 5. Petals wanting. Stamens numerous, exserted. Carpels commonly few, 

 one-seeded, ribbed or nerved, stipitate or nearly sessile. Meadow Rue. Maid-of-the- 



MlST. 



Flowers perfect : filaments petal-like. 



Achenes curved along the upper edge, the body longer than the stipe. 1. T. clavaium. 



Achenes straight along the upper edge, the body shorter than the stipe. 2. T. mirabile. 



Flowers dioecious or polygamous: filaments not petal-like. 

 Filaments subulate or filiform. 



Flowers strictly dioecious: leaflets not waxy beneath. 

 Stamens less than 18. 



Stems procumbent: leaflets 6-15 mm. broad, not glaucous : achenes 



3.5-4 mm. long. 3. T. debile. 



Stems erect or ascending : leaflets 2-7 mm. broad, glaucous beneath : 



achenes 3-3.5 mm. long. 4. T. Texanuvi. 



Stamens more than 18. 



Leaflets longer than broad. 



Roots not vellow: petioles barely dilated at the baso. 5. T. dioiciim. 



Roots bright yellow : petioles widely dilated at the base. 6. T. cnriaceum. 



Leaflets broader than long. 7. T. caulophyllmdes. 



Flowers polygamous : leaflets more or less glandular or waxy beneath. 8. T. purpiirascenn. 



Filaments spat'ulate. often broader than the anthers. 



Leaflets entire or nearly so: flowers nearly dioecious: achene-body 3-4 



mm. long. 9. T. macrosstylum. 



Leaflets strongly lobed : flowers polygamous : achene-body 4-5 mm. long. 10. T. polygamuni. 



