238 ONAGRACEiE. Ludwigia. 



MidiT. fl. \. p.S9; Pursk, f.l. p.UO; Torr. ft. 1. p. ISO ; Bart. Jl. N. Am. 1. t. 14. 

 Isnardia allcrnifolia, DC. prodr.S.p. 122; Beck, hot. p. 119; Darlingt. fl. Cest. p. 109. 



Perennial. Stem 2-3 feet high, slightly pubescent or almost smooth, purplish, much 

 branched, marked with elevated lines descending from the bases of the petioles. Leaves 

 2-4 inches long, the lateral veins uniting so as to form a continuous line within the margin. 

 Pedicels 2-4 lines long. Bracteoles lanceolate, acute, situated close to the flower. Calyx- 

 segments longer than the ovarj', becoming purple on the inside. Petals yellow, roundish- 

 obovate, caducous. Stamens much shorter than the petals : anthers large, oblong. Style 

 tliick : stigma obscurely 4-Iobed. Capsule globose-cubical, crowned with the large dilated 

 base of the style, opening at first by a small hole left by the separation of the deciduous style ; 

 afterward, the summit (stylopodium) of the capsule falls off. Seeds very numerous, attached 

 to a large central placenta. 



In swamps ; common. July - August. 



2. Ludwigia sph.«rocarpa, Ell. (Plate XXIX.) Round-fruited Ludwigia. 

 Whole plant nearly smooth ; stem erect, much branched ; leaves narrowly lanceolate, 



mostly acute, attenuate at the base ; flowers solitary, axillary, or r.lnstered towards the summit 

 of the branches, and appearing as if in leafy interrupted spikes, apetalous ; bracteoles minute 

 or wanting ; lobes of the calyx as long as the capsule, triangular-ovate ; capsules turbinate- 

 globose, obscurely 4-sided, canescent, crowned with the deeply 4-lobed stylopodium. — EU. 

 sk. \. p. 211 ; Torr. ^ Gr.fl. N. Am. I. p. 524. Isnardia sphaerocarpa, DC. prodr. 3. p. 61. 



Perennial. Stem about 2 feet high, slightly pubescent above, smooth below, of a reddish 

 tinge. Leaves of the stem 3-5 inches long, of the branches about 2 inches, remotely and 

 obscurely repand-denticulate with a long tapering base, nearly smooth ; the veins confluent 

 near the margin. Flowers in somewhat compound leafy spikes. Calyx pubescent ; the 

 segments a little spreading. Petals none. Stamens scarcely half the length of the sepals : 

 anthers broader than long ; the lobes rather remote. Stigma oval, not lobed. Capsule about 

 2 lines long, crowned with the reddish depressed stj'lopodium, which is deeply divided into 4 

 obtuse lobes. Seeds oval. 



In water near PeekskOl {Mr. R. I. Brownne). July - August. 



V 



§2. Isnardia, Linn. Leaves opposite, mostly petioled : flowers sessile : petals very small or none: 

 capsules short, truncate at the apex. 



3. Ludwigia palustris, Ell. Water Purselane. 

 Plant smooth and slightly succulent ; stems procumbent, rooting or floating at the base ; 



leaves ovate-spatulate, shining, tapering into a slender petiole ; flowers axillary, apetalous, 

 or with small purplish petals ; lobes of the calyx very short ; capsules oblong, 4-sided, not 

 attenuate at the base. — Ell. sk. 1. p. 214 ; Torr. <^ Gr. fl. N. Am. 1. p. 525. L. apetala, 

 Wali.fl. Car. p. 89. L. nitida, Michx.fl. 1. p. 87 ; Pursh,fl. 1. p. 111. Isnardia palustris, 



