The Flora of the Cayuga Lake Basin 313 



94. ONAGRACEAE (Evening Primrose Family). 



a. Parts of the flower in 4's or more numerous. 



b. Hypanthium scarcely or not at all extended beyond the ovary. 

 c. Capsule obovoid-cubical ; seeds naked; sepals persistent; petals minute and 



reddish, or wanting. 1. Ludvigia 



c. Capsule linear ; seeds comose ; sepals deciduous ; petals larger, obovate or 

 obcordate, purple or white. 2. Epilobium 



b. Hypanthium conspicuously extended beyond the ovary ; seeds naked. 

 c. Fruit dehiscent; flowers yellow. 3. Oenothera 



c. Fruit indehiscent ; flowers pale pink. 4. Gaura 



a. Parts of the flower in 2's; flowers minute, white; fruit uncinate-hairy. 



5. ClRCAEA 



1. Ludvigia L. 

 1. L. palustris (L.) Ell. Water Purslane. 



Ditches and wet shores, usually in muddy situations, in both calcareous and non- 

 calcareous districts; common, and generally distributed. Aug.-Sept. 



N. S. to Man. and Oreg., southw. to Fla., La., Calif., and Mex., and on the 

 Atlantic Coastal Plain. Widely distributed in the Old World. 



2. Epilobium L. 



a. Petals 10-20 mm. long; stigma 4-lobed. 



b. Stamens and style declined ; petals entire ; hypanthium not prolonged beyond 

 the ovary; plant glabrous or puberulent above. 1. E. angustifolium 



b. Stamens and style erect ; petals notched ; hypanthium slightly prolonged ; 

 plant hirsute. 2. E. hirsutum 



a. Petals 9 mm. long or less ; stigma entire. 



b. Stems terete, with no decurrent lines from the leaf bases; leaves linear or 

 lanceolate, entire or nearly so, the margins revolute. 

 c. Capsules and stems velvety with spreading pubescence. 3. E. molle 

 c. Capsules and stems crisp- and subappressed-puberulent, canescent. 



4. E. densum 

 b. Stems with decurrent lines from the leaf bases ; leaves lanceolate or ovate, 

 usually toothed, the margins flat. 

 c. Seeds obconic- fusiform, 1.5 mm. long, not striate, beakless; coma bright 

 tawny to dirty white ; flowers pinkish ; leaves narrowed at base, closely 

 and irregularly serrate ; nearly mature fruit erect or suberect ; plant, when 

 well developed, bushy, dense. 5. E. coloratum 



c. Seeds obovoid, 1 mm. long, distinctly striate, short-beaked when coma is re- 

 moved ; coma white ; flowers bluish pink or bluish purple ; leaves more 

 rounded at base, more remotely serrate ; nearly mature fruit spreading ; 

 plant, when well developed, usually more strict and open, not bushy. 

 d. Plant tall, puberulent above ; leaves nearly or quite sessile. 



6. E. glandulosum, 

 var. adenocaulon 

 d. Plant low, nearly or quite glabrous ; leaves flaccid, more nearly entire, 

 more gradually narrowed to a distinct petiole. 6a. E. glandulosum, 



var. perplexans 

 1. E. angustifolium L. Fireweed. Willow Herb. 



Dry or damp banks and open woodlands, especially in recently burned clearings, 

 in gravelly, nearly neutral or acid, soils ; common, and generally distributed. July- 

 Aug. • 



Greenland to Alaska, southw. to N. C, Ind., Kans., Ariz., and Calif., including the 

 Atlantic Coastal Plain. Found also in Eu. and Asia. 



