158 ELEMENTS OF BOTANY. 



4. R. LUTEA Walt. Yellow INIeadow-beauty. Stem erect, 

 widely branched, 4-angied, bristly, 10-15 in. high; lower leaves spatu- 

 late or obovate, the upx^er lanceolate and acute, all nearly smooth, 

 margin bristly serrulate ; flowers numerous, about 1 in. wide ; calyx 

 tube short, smooth, much constricted, the lobes cuspidate ; petals 

 yellow; stamens straight, erect. June- August. Damp woods. 



88. ONAGRACEiE. EVENING PRIMROSE FAMILY. 



Herbs, or rarely shrubs ; leaves simple, opposite or alter- 

 nate, exstipiilate but sometimes with basal glands ; flowers 

 solitary, spiked or racemed ; calyx adherent to the ovary, 

 and often prolonged, into a tube beyond it, usually 4-lobed ; 

 petals distinct, usually 4, sometimes none; stamens 4 or 8, 

 inserted with the petals at the top of the calyx tube ; ovary 

 1-6-celled, style 1, simple or 4-parted ; fruit a capsule or 

 berry, dehiscent or indehiscent, 1-many-seeded. 



I. LUDWIGIA. 



Perennial herbs, often stoloniferous ; leaves simple, oppo- 

 site or alternate, entire ; flowers axillary or terminal ; calyx 

 tube not prolonged beyond the ovary, cylindrical or obconic, 

 usually crowned with 4 persistent lobes ; petals 4, roundish 

 or obcordate, often wanting; stamens 4, short; style capitate 

 or 4-lobed ; capsule 4-5-celled, winged or angled, many-seeded. 



1. L. ALATA Ell. Winged Ludwigia. Stem erect, smooth, 

 simple or branched, winged, often stoloniferous, . 2-3 ft. high ; leaves 

 alternate, oblanceolate or almost linear, nearly or quite sessile, 

 obscurely dentate ; flowers axillary or in terminal spikes, small, ses- 

 sile; calyx glabrous; petals none; capsule cubical or obpyramidal, 

 angles winged; seeds ovoid, faintly pitted. June-September. On 

 marshy ground. 



2. L. hirtella Raf. Haiky Ludwigia. Stem erect, slender, 

 simple or sparingly branched, hairy, 2-3 ft. high ; leaves alternate, 

 lanceolate or oblong, obtuse at the apex, sessile and rounded at the 

 base, hirsute ; flowers axillary, on 2-bracted pedicels ; calyx lobes 

 erect or spreading, lanceolate, acute, about half as long as the yellow, 

 obovate petals, and longer than the cubical, hairy capsule. June- 

 September. In flat pine barrens. 



