428 ONAGRACEAE 
1. O. biennis, (L.) Scop. (Fig. 5, pl. 104.) Eventne Primrose. 
Stout, erect, 1 to 9 ft. high, slightly branching, with a few or many downy 
hairs. Leaves lance-shaped to oblong, narrowed at base and somewhat 
clasping, | to 6 in. long. Flowers bright yellow, opening in the evening, 
about 2 in. broad. Calyx adherent to ovary and much longer than the 
latter. Capsule hairy. In waste places. Common, June-Oct. 
2. ©. cruciata, (Nutt.) Small. SMALL-FLOWERED EvENING PRIM- 
ROSE. Similar to No. 1, but petals are lance-shaped and much smaller 
than those of O. biennis. June-Oct. 
3. O. Oakesiana, (A. Gray) Britton. OAaKeEs’s Eventna PRIMROSE. 
Resembles No. 1, but is more slender, leaves generally narrower, and 
plant not hairy or with few hairs. Flowers about 4 as broad as those of 
No. 1. Capsule about 1/3 longer than that of No. 1. Dry waste places 
in northern section of our area. June-Oct. 
6. OENOTHERA, L. 
Similar to Onagra, but seeds not compressed and not angular. 
1. O. humifusa, Nutt. (Fig. 4, pl. 104.) Stasme Evenine Prim- 
ROSE. Plant, ? to 13 ft. high, much branched, generally reclining, cov- 
ered with a silvery down. Leaves narrow with wavy, somewhat toothed, 
margins 4 to 2 in. long. Flowers yellow, from the leaf-axils, not numer- 
ous, 1/2 to 2/3 in, across. Sea beaches, New Jersey and southward. . 
June-Sept. 
2. ©. laciniata, Hill. SmNUATE-LEAVED EveNING PRIMROSE. Plant, 
about the size of the last. Leaves deeply waved, the sinuses reaching 
nearly to mid-vein. Hairs not silvery and much less dense than in No, 1. 
Sandy soil, New Jersey, Pennsylvania and westward. May-June. 
7. KNEIFFIA, Spach. 
Herbs, usually more slender than the species of Onagra. Leaves mostly 
narrow, without teeth or with low teeth. Flowers yellow in terminal 
clusters, petals 4, calyx segments 4. Stamens 8, the alternate ones longer. 
Ovary 4-angled; pistil 4-cleft at summit. Seeds numerous, not angled. 
Plants not covered with coarse hairs. 
Leaves without teeth or divisions. 
Plants: reclimitig. . ¢)50) Se ien core cet ieeeiien cee) te. S60 agence 
Plants: ‘erect; So%) a) sdasge to Wal Vee vetoes, fat wat) | xt Simran 
Leaves with toothed or wavy borders. 
Foot-stalk of the capsule longer than the capsule . K. longipedicellata 
Foot-stalk of the capsule shorter than the capsule. 
Leaves broadest toward the apex . . . . . .« K. linearis 
_ Leaves broadest toward base . . . . .- © - K. fruticosa 
Plants covered ‘with coarse airs .»\.1-.0% Us Sermeree, fle + 0) wRROeRORORene 
1. K. Alleni, Small. Atien’s Sunprors. Plant, reclining, much 
branched, stems from 3 in. to 2 ft. long. Leaves inversely lance-shaped 
without teeth; the whole plant covered with fine down. Flowers yellow 
2/3 to 1 in. broad in more or less terminal clusters, Capsule 4-angled, 
winged, nearly globe- or pear-shaped, on a foot-stalk longer than itself. 
Sandy places on Long Island. June-Aug. 
2. K, longipedicellata, Small. (Fig. 3, pl. 104.) Lona-stemMED 
