232 FLORA OF FHILAVFLFHIA. 



Seeds naked. 



Stamens 4, in one row. 



Leaves opposite; stems creeping or floating. 



1. Isnardia. 

 Leaves alternate ; stems erect or ascending. 



2. Ludwigia. 

 Stamens 8-12, in 2 rows. 3. Jussiaea. 



Seeds furnished with a tuft of silky hairs. 4. Chamaenerion. 

 Calyx-tube prolonged beyond the ovary. 



Seeds furnished with silky hairs. 5. Epilobium. 



Seeds naked or sometimes tuberculate. 

 Stamens equal in length. 



Ovules and seeds horizontal, inserted in 2 or rarely 



more rows, prismatic-angled. 6. Onagra. 



Ovules and seeds ascending, not angled. 



7. Oenothera. 

 Stamens unequal in length, the alternate ones longer. 



8. Kneiffia. 

 Fruit indehiscent, nut-like. 9. Gaura. 



Floral whorls of 2 parts. 10. Circaea. 



1. ISNARDIA L. 



1. Isnardia palustris L. Water Furslane. M. p. 652. Muddy ditches and 

 swamps. Summer and fall. 



2. LUDWIGIA L. 



Flowers inconspicuous ; petals none, or small, yellowish or greenish ; valves 

 of the capsule separating from the terminal disk. 

 Capsules subglobose ot top-shaped. 1. L. sphaerocarpa. 



Capsules cylindric or obpyramidal. 2. L. linearis. 



Flowers showy, peduncled; petals large, bright yellow; capsules opening by 

 an apical pore. 

 Plants hirsute ; capsules bristly-pubescent. 3. L. hirtella. 



Plants glabrous or nearly so ; capsules glabrous. 4. L. alternifolia. 



1. Ludwigia sphaerocarpa Ell. M. p. 653. Swamps. Summer. 



BmcA-s— Bristol (Fr.). 



Burlington — Atsion. Gloucester — Near Mickleton Junction (He.). 

 iSaHein— Manington (C), Cumberland, Millville (Je.) (Re.). Atlantic— 

 Hammonton (Cr.) (Ke.) (Pr.), Egg Harbor (Ja.), May's Landing (Le.). 

 Cape May — Woodbine (Br.). Mercer— Mercerville (VP.). 



New Castle— Townsendi, Canby and Tatnall. 



2. Ludwigia linearis Walt. M. p. 654. Swamps. Summer. 



Burlington— Atsion (Fr.). Cape Mai/— Woodbine (St.). Atlantic— 

 Hammonton (Ke.), May's Landing (Li.), Egg Harbor (Wn.). 



3. Ludwigia hirtella Raf. M. p. 654. Moist pine-barrens. Summer. 



Burlington— Batsto, Quaker Bridge (C), Atsion (Fr.). Atlantic— 

 Hammonton, Main Road Station (C). 



4. Ludwigia alternifolia L. Seed-box. M. p. 654. Swamps. Summer. 



3. JUSSIAEA L. 

 1. Jussiaea diffusa Forskl. M. p. 654. Ponds. Summer. 

 Cowden- Kaighn's Point, Mart, and I. BurJc (Fu.). 



