ONAGKACEAE. 



Family 7. ONAGRACEAE Dumort. 



Evening-Primrose Family. 



Herbs, or rarely shrubs, with alternate or opposite leaves, no stipules 

 or mere glands in their places, and generally perfect flowers. Calyx-tube 

 adnate to the ovary, the limb 2-6-lobed (usually 4-lobed). Petals 2-9 

 (usually 4), convolute in the bud, rarely none. Stamens usually as many 

 or twice as many as the jDetals. Ovary 1-6-celled (usually 4-celled) ; styles 

 united; stigina capitate, discoid or 4-lobed; ovules generally anatropous. 

 Fruit a capsule or small nut. Endosperm very little or none. Forty genera 

 and about 350 species of wide geographic distribution, most abundant in 

 America. 



Calyx-tube not prolonged beyond the ovary ; aquatic plants. 

 Calyx-tube prolonged beyond the ovary ; land plants. 



Stamens all of equal length. 



Alternate stamens longer. 



1. Isnardia. 



2. Raimannia. 



3. Hartmannia. 



1. ISNARDIA L. 



Succulent herbs, mostly glabrous, aquatic or uliginous. Stems creeping 

 or floating; leaves opposite, relatively few, petioled. Flowers axillary, not 

 yellow. Calyx-segments 4, shorter than the tube or slightly longer. Petals 

 4, small, or wanting. Filaments very short. Ovary very short; styles often 

 almost wanting. Capsule obovoid or turbinate, straight. [In honor of Antoine 

 Dante Isnard, a French botanist, and a member of the Academy of Sciences, 

 died 1724.] About 4 species in Europe, Asia, continental North America, 

 Mexico and the West Indies. Type species: Isnardia paluMris L. 



Fruit l*"-2" long. 

 Fruit 3"-4" long. 



1. /. palustris. 



2. I. repens. 



1. Isnardia palustris L. 



Marsh Purslane. (Fig. 

 286.) Stems branching, 4'- 

 20' long. Leaves oval, ovate 

 or spatulate, 6"-12" long, 

 narrowed into slender peti- 

 oles; flowers solitary, about 

 1" broad; bractlets at base 

 of the calyx usually none; 

 calyx-lobes triangular, acute ; 

 petals small, reddish, or 

 often wanting; capsule 4- 

 sided, slightly longer than 

 wide, about IV' high, slightly 

 or somewhat exceeding the 

 calyx lobes. [Ludivigia 



palustris Ell.] 



Pembroke Marsh, 1905. 

 Native. North temperate zone 

 and Santo Domingo. Flowers 

 from spring to autumn. Its 

 seeds were, presumably, trans- 

 ported to Bermuda by a bird. 



