234 ONOGRACE^. CEnothera. 



2. CENOTHERA. Linn. ; Torr. ^ Chr. fl. N. Am. 1. p. 491. evening primrose. 



[ Named from the Greek, oinos, nine, and Viero, to hunt ; the roots being incentives to wine-drinlung.] 



Tube of the calyx prolonged above the ovary, deciduous : segments 4, reflexed. Petals 4, 

 equal, obcordate or obovate, scarcely clawed. Stamens 8. Ovary 4-celled, v?ith numerous 

 ovules in each cell. Stigma 4-lobed or capitate. Capsule 4-valved, many-seeded ; the 

 dissepiments often disappearing. Seeds naked. — Herbs or rarely suffrutescent plants, with 

 alternate leaves. Flowers showy, often opening towards evening. 



&. EuiENOTHERA. Stigma ^-parted ; the lobes elongated : anthers linear, fixed by the middle : petals 

 yellow, sometimes turning to rose-color in fading. 



1. CEnothera biennis, Linn. Common Evening Primrose. 



Stem erect, mostly simple, usually hairy ; leaves ovate-lanceolate, repandly denticulate, 

 acute, pubescent ; flowers in a terminal somewhat leafy spike ; tube of the calyx much longer 

 than the ovary, and mostly twice as long as the calyx ; capsules sessile, oblong, slightly 

 tapering upwards, obscurely 4-angled. — Linn. sp. 1. p. 346 ; Michx. fl. 1. p. 224; Engl, 

 hot. t. 1534 ; Pursh, fl. 1. p. 261 ; Ell. sk. 1. p. 441 ; Torr. fl. 1. p. 387; Bigel. fl. Bost. 

 p. 148 ; DC. prodr. 3. p. 46 ; Beck, hot. p. 118 ; Darlingt. fl. Cest. p. 240. 



Root annual or biennial. Stem 2-5 feet high, more or less hairy and sometimes rough, 

 branching, terete. Leaves 3-6 inches long, tapering at each end ; the lower ones on short 

 petioles. Spike 3-12 inches long. Calyx yellowish-green; the tube above the ovary 1-2 

 inches long : segments at first more or less cohering, splitting on one side by the expansion of 

 the flower, finally more or less distinct, less than half the length of the tube. Petals variable 

 in size, usually about three-fourths of an inch long, but sometimes nearly twice as large, ob- 

 cordate. Stamens shorter than the petals, a little unequal : anthers versatile. Style filiform : 

 lobes of the stigma spreading. Capsule somewhat cylindrical, about an inch long. Seeds in 

 two rows in each cell. 



Fields and moist meadows ; common. July - September. This plant has become na- 

 turalized in many parts of Europe. It presents several varieties, which have been regarded 

 as species by some botanists ; such as CE. muricata, Murr., grandiflora, Ait., parviflora, 

 Linn., and cruciata, Nutt. 



2. CEnothera fruticosa, Linn. Sundrops. 



Hairy or almost smooth ; stem erect ; leaves lanceolate or oblong-lanceolate, repandly 

 denticulate ; corymb peduncled, naked below, elongated in fruit ; tube of the calyx much 

 longer than the ovary ; petals broadly obcordate, longer than the acuminate calyx-segments 

 and stamens ; capsule oblong-clavate, 4-winged, with intermediate ribs, longer than the pedi- 



