ONAGRACEAE. 



VOL. II. 



2. Ludwigiantha brevipes Long, n. sp. Short-stalked 

 Ludwigiantha. Fig. 3015. 



Similar to the preceding species, creeping, glabrous. Leaves 

 oblong-oblanceolate, acutish at the apex, narrowed to the sessile 

 or nearly sessile base; flowers about \' broad, on slender pedun- 

 cles shorter than the leaves ; calyx-lobes lanceolate to ovate- 

 lanceolate; filaments about i" long; filaments and stout style 

 about i" long; capsule a little longer than the calyx-lobes. 



Moist sand, Long Beach Island, Ocean County, New Jersey. July- 

 Aug. 



3. LUDWIGIA L. Sp. PI. 118. 1753. 



Perennial or annual herbs, with alternate usually entire leaves, 

 and axillary or terminal, yellow or greenish flowers. Stems erect 

 as ascending, sometimes angled, or winged. Calyx-tube cylindric, 

 obpyramidal or top-shaped, not prolonged beyond the ovary, 

 3~5-lobed (usually 4-lobed), the lobes generally persistent. Petals 

 usually 4, sometimes none, inserted under the margin of the disk. Stamens usually 4, inserted 

 with the petals; filaments short. Ovary 4~5-celled; stigma capitate or 4-lobed. Capsule terete, 

 ribbed or winged, crowned with the calyx-lobes, many-seeded, septicidally or irregularly de- 

 hiscent, or opening by an apical pore. [Named in honor of C. G. Ludwig, 1709-1773, Pro- 

 fessor of Botany at Leipsic.] 



About 25 species, natives of warm and temperate regions, most abundant in North America. 

 Besides the following about 12 others occur in the southern and southwestern states. Type species: 

 Ludwigia alternifolia L. 



Flowers inconspicuous ; petals none, or small, yellowish or greenish ; valves of the capsule separat- 

 ing from the terminal disk. , 

 Capsules subglobose or top-shaped. 



Bractlets at the base of the calyx minute, or none ; capsule subglobose, finely pubescent. 



i. L. sphaerocarpa. 

 Bractlets at the base of the calyx linear, about equalling the capsule : 



glabrous. 



Capsules cylindric or obpyramidal. 

 Capsules cylindric. 

 Capsules obpyramidal. 



Capsules as long as broad, or broader, the angles winged. 4. L. alata. 



Capsules several times longer than broad, the angles obtuse. 5. L. linearis. 



Flowers showy, peduncled ; petals large, bright yellow ; capsules opening by an apical pore. 



Plants hirsute ; capsules bristly pubescent. 6. L. hirtclla. 



Plants glabrous ; capsules glabrous. 7- L. alternifolia. 



i. Ludwigia sphaerocarpa Ell. Globe- fruited Ludwigia. Fig. 3016. 



Ludivigia rudis Walt. Fl. Car. 89. 1788. ? 

 Ludwigia sphaerocarpa E\\. Bot. S. C. i : 213. 1817. 



Erect, branching, generally finely pubescent, 

 stoloniferous, 2-3 high, the lower part of the 

 stem clothed with aerenchyma when growing 

 in water. Leaves alternate, sessile, those of 

 the stem and branches lanceolate, acute at both 

 ends, 2'-4' long, scabrous and minutely den- 

 ticulate, those of the stolons obovate ; flowers 

 solitary, sessile, greenish, about ii" broad; 

 bractlets at base of calyx minute or none; 

 calyx-lobes triangular-ovate, acute; petals 

 commonly none ; capsule subglobose, about 2" 

 high, scarcely longer than the calyx-lobes, 

 finely pubescent. 



In swamps, eastern Massachusetts to southern 

 New York and Florida, west to Louisiana. July- 

 Sept. 



capsule top-shaped, 



2. L. polycarpa. 



3. L. glandulosa. 



