168 ONAGRACEAE 



1. JUSSIAEA L. Sp. PI. 388. 1753. 



Perennial herbs with alternate leaves. Flowers yellow, solitary in leaf-axils, pediceled. 

 Hypanthium not prolonged above ovary. Sepals (in ours) 5, green, quite persistent. 

 Petals 5, obovate, spreading. Stamens twice the number of petals. Ovary (in ours) 5- 

 celled, many-ovuled; stigma capitate. Capsule cylindric-clavate. Seeds (in ours) in 1 

 row in each cell, covered by a layer from the capsule wall. [Named for Bernard de 

 Jussieu, 1699-1777, founder of the Natural System of Botany.] 



About 40 species, in the warm and temperate regions, particularly of America. Type species, Jtissiaea 

 repens L. 



1. Jussiaea repens var. peploides (H.B.K.) Griseb, Yellow Water Weed. 



Fig. 3352. 



Jussiaea peploides H.B.K. Nov. Gen. & Sp. 6: 97. 1823. 

 Jussiaea repens var. peploides Griseb. Cat. PI. Cubens. 107. 1866. 

 Jussiaea repens var. californica S. Wats. Bot. Calif. 1: 217. 1876. 

 Jussiaea californica Jepson, Fl. W. Mid. Calif. 326. 1901. 



Glabrous perennial herbs with decumbent stems rooting freely at the nodes, 3 to many dm. 

 long. Leaves oblong to spatulate-oblong, obtuse to acute, subentire, plainly and evenly pinnate- 

 veined, the blades 1-4 cm. long, on petioles 1-2.5 cm. long or longer on 'floating leaves; pedicels 

 1-4 cm. long in fruit ; flower pubescent about the base of stamens and style ; sepals lanceolate, 

 4-7 mm. long ; petals yellow, obovate, pinnately veined, 10-14 mm. long ; stamens about one- 

 third as long ; pistil as long as stamens, sometimes somewhat pubescent at base ; stigma globose ; 

 capsule hard, quite cylindric, about 2 cm. long, at length reflexed and the sepals deciduous from 

 the mature fruit ; seeds large for the order, with a very thick, tough outer coat. 



In wet places, Upper Sonoran Zone; Oregon south through the western United States to Central America 

 and South America. Type locality: "in humidis convallis Combeimensis, prope urbem Ibague^" Colombia. May- 

 Sept. 



2. LUDWIGIA L. Sp. PI. 118. 1753. 



Perennial herbs of marshes and wet places ; ours with opposite leaves and 4-merous 

 flowers, though the petals may be lacking. Ours with 4 stamens, alternate with the petals 

 and with short filaments. Ovary in ours usually flattened at the broad apex. Capsule in 

 ours short, many-seeded, 4-valved, dehiscent laterally and septicidally or by terminal pores. 

 Seeds minute. [Named in honor of C. G. Ludwig, 1709-1773, professor of botany at 

 Leipzig.] 



A genus of about 30 species, of warm and temperate regions, most abundant in North America. Type species, 

 Ludwigia alternifolia L. 



Hypanthium and capsule with 4 evident longitudinal green bands; bracteoles basal, not more than 1 mm. long or 



not evident. 1. L. palustris. 



Hypanthium and capsule without green bands; bracteoles above the base and 1-5 mm. long. 2. L. nutans. 



1. Ludwigia palustris var. americana (DC.) Fern. & Griscom. American 



Marsh Purslane. Fig. 3353. 



Ludwigia apetala Walt. Fl. Car. 89. 1788. 



Isnardia palustris P americana DC. Prod. 3: 61. 1828. 



Ludwigia palustris \zr. americana Fern. & Griscom, Rhodora 37: 176. 1935. 



Glabrous, with stems creeping or floating and with erect branches 1-3 dm. tall. Leaves lan- 

 ceolate to elliptic-ovate, subentire, acute, the blades 1-2.5 cm. long, usually at least half as wide 

 as long, long-petiolate ; flowers solitary, axillary, sessile ; sepals deltoid, acute, persistent, 1-2 mm. 

 long ; petals lacking ; stamens about 1 mm. long ; stigma 4-lobed ; capsule 3-5 mm. long, oblong, 

 2-3.5 mm. broad, somewhat 4-angled; seeds yellowish, broadly obovoid, 0.5 mm. long. 



About ponds and muddy places. Transition and Canadian Zones; Cascade Mountains of Washington and 

 Oregon south to the Sierra Nevada, California; also throughout the United States and in Canada, Mexico, and 

 Central America. Type locality: eastern North America. June-Sept. 



Ludwigia palustris var. pacifica Fern. & Griscom, Rhodora 37: 176. pi. 249. figs. 5, 9. 1935. Leaves mostly 

 short-petiolate, leaf-blades of terrestrial form mostly more than 1 cm. long, and one-third to one- fourth as wide; 

 sepals acuminate; capsules 2-2.8 mm. thick. Ponds and muddy places along the coast and in the Coast Ranges 

 from British Columbia to central California. Type locality: Sproat Lake, Vancouver Island, British Columbia. 



2. Ludwigia natans var. stipitata Fern. & Griscom. Southern Marsh Purslane. 



Fig. 3354. 



Ludwigia natans var. stipitata Fern. & Griscom, Rhodora 37: 175. pi. 349. figs. 1, 4. 1935. 



Habit as in preceding species. Leaf-blades up to 4.5 cm. long, rhombic-ovate, petiolate; 

 flowers solitary, axillary, short-pedicillate ; sepals triangular-acuminate; petals shorter than the 

 sepals, easily shed; pedicel of the capsule 2-4 mm. long; capsule 6-8 mm. long, 3-3.5 mm. broad, 

 somewhat 4-angIed, light brown without longitudinal green bands. 



Muddy places in ponds and marshes. Lower Sonoran Zone; San Bernardino Valley, San Bernardino County. 

 Known only from the type locality. Aug.-Sept. 



