EPILOBIACEAE 837 



glabrous, nearly as broad as long, almost as long as the capsule : petals wanting : capsules 

 3-4 mm. high, the angles winged. 



In marshes, North Carolina to Missouri, Florida and Louisiana. Spring to fall. 



8. Ludwigia lanceolata Ell. Stems glabrous, erect, 3-7 dm. tall, angled or some- 

 times winged, often much branched, sometimes stoloniferous : leaf -blades linear-oblanceolate 

 to linear-lanceolate, 2-10 cm. long, acute, entire, sessile, those of the stolons suborbicular 

 or spatulate : flowers inconspicuous : sepals glabrous, about as long as the capsule, broader 

 than long, acute : petals wanting : capsules cubic-turbinate, about 4-5 mm. high, the angles 

 margined, about twice as long as the sepals. 



In swamps, North Carolina to Florida. Summer and fall. 



9. Ludwigia sphaerocarpa Ell. Stems generally finely pubescent, 6-9 dm. high, the 

 lower part clothed with aerenchyma when growing in water : leaf-blades variable, those of 

 the stem and branches lanceolate, acute at both ends, 5-10 cm. long, scabrous and minutely 

 denticulate, sessile, those of the stolons obovate : flowers sessile : sepals triangular, acute': 

 petals commonly wanting : capsules globular, about 4 mm. high, scarcely longer than the 

 sepals. 



In swampg, eastern Massachusetts to Florida and Louisiana. Summer and fall. 



10. Ludwigia pilosa Walt. Stems woody, rather densely pilose, erect or assurgent, 

 6-12 dm. tall, nearly terete, usually much branched, often stoloniferous : leaf-blades lance- 

 olate, oblong or linear-oblong, 1-6 cm. long, acute, sessile or nearly so, those of the branches 

 much smaller than those of the stem, those of the stolons more or less spatulate : flowers 

 inconspicuous : sepals silky when young, triangular-ovate, acuminate : petals minute or 

 wanting : capsules subglobose-cubic, 4-6 mm. in diameter, hoary, sessile. 



In swamps, North Carolina to Florida and Louisiana. Summer and fall. 



11. Ludwigia glandulosa Walt. Stems glabrous, much branched, 3-9 dm. tall : 

 leaf-blades oblong-lanceolate, acute at each end, 5-10 mm. long, sessile or short-petioled : 

 flowers axillary, rarely 2 together : bractlets at the base of the hypanthium minute or 

 wanting : sepals triangular-ovate, acute : petals wanting : capsules 4-grooved, 6-8 mm. 

 long, glabrous, 4-5 times as long as the sepals. 



In swamps, Illinois to Kansas, South Carolina, Florida and Texas. Summer and fall. 



12. Ludwigia linifolia Poir. Stems glabrous, erect or assurgent, 1-5 dm. tall, sim- 

 ple or diffusely branched, often purplish, stoloniferous at the base, 4-angled : leaf-blades 

 linear-oblanceolate or linear, 2-6 cm. long, obtuse or acute, sessile or nearly so : flowers 

 inconspicuous, sessile : sepals glabrous, lanceolate or ovate-lanceolate, acuminate : petals 

 about as long as the sepals : capsules cylindric, 1 cm. long, sessile. 



In pine-land swamps, North Carolina to Florida and Alabama. Spring to fall. 



13. Ludwigia linearis Walt. Stems glabrous, 3-7.5 dm. high, branching, often 

 stoloniferous, the lower part clothed with aerenchyma : leaf-blades narrowly linear, ses- 

 sile, acute at each end, 2.5-5 cm. long, about 2 mm. wide, with roughish margins, those 

 of the stolons obovate : flowers sessile : sepals triangular-ovate, acute : petals yellowish, 

 slightly longer than the sepals : capsules narrowed at the base, 6-8 mm. long, 3-5 times as 

 long as the sepals. 



In swamps, New York to Florida and Louisiana. Summer and fall. 



14. Ludwigia hirtella Raf. Stems hirsute, branching, 3-6 dm. tall : leaf-blades ob- 

 long-lanceolate or ovate-lanceolate, 2.5-3 cm. long, obtuse at the apex, rounded at the 

 base, sessile : flowers solitary, peduncled : corolla 20-30 mm. broad : sepals ovate-lanceo- 

 late, acute : corolla 12-20 mm. broad : petals yellow, longer than the sepals : capsules cubic 

 above a rounded base, about 5 mm. high, shorter than the sepals, each opening by an 

 apical pore. 



In swamps, mainly in pine lands, New Jersey to Florida and Texas. Spring to fall. 



15. Ludwigia virgata Michx. Stems from more or less thickened tuberous roots, 

 slender, puberulent, erect or ascending, 4-13 dm. tall, simple and wand-like or branched 

 at the base or above, angled, especially above : leaf -blades variable, the lower ones mostly 

 oval or oblong, 1-5 cm. long, the upper linear, 2-10 cm. long, all obtuse or minutely apicu- 

 late, sessile : flowers in elongated interrupted racemes: pedicels 8-15 mm. long: sepals puber- 

 ulent, ovate, acute, reflexed : corolla bright yellow, 3-4 cm. broad : petals about twice as 

 long as the sepals : capsules globular-cubic, 5-8 mm. long, the angles often slightly winged. 



In dry pine lands, North Carolina to Florida and Louisiana. Spring to fall. 



16. Ludwigia alternifolia L. Stems glabrous or puberulent, often from tuberous 

 roots, branching, 6-12 dm. high : leaf-blades lanceolate, acute or acuminate at the apex, 

 5-12 cm. long, short-petioled : flowers short-peduncled, axillary : sepals ovate, acuminate : 

 corolla 12-16 mm. broad : petals about equalling the sepals, falling away when the plant 



