486 ONAGRACEAE, [Vor. II. 
2. Onagra biénnis (L,.) Scop. 
Common Evening-Primrose. Night 
Willow-herb. (Fig. 2579.) 
OEnothera biennis L.. Sp. Pl. 346. 1753. 
OE. muricata I,. Syst. Ed. 12, 263. 1767. 
Erect, generally stout, annual or bien- 
nial, simple and wand-like or branched, 
1°-9° high, more or less hirsute-pubes- 
cent, rarely glabrate. Leaves lanceolate, 
acute or acuminate, narrowed and sessile 
at the base or the lowest petioled, repand- 
denticulate, 1/-6’ long; flowers spicate, 
terminal, leafy-bracted, bright yellow, 
opening in the evening, 1/-2’ broad; 
calyx-tube slender, much longer than the 
ovary, the lobes linear, contiguous at the 
base, reflexed ; capsules oblong, narrowed 
above, erect, pubescent, 34 ’—1/ long, 214//— 
3/’ thick, nearly terete; seeds angled. 
Usually in dry soil, Labrador to Florida, 
west to the Rocky Mountains. Naturalized 
inthe Old World. June-Oct. 
Onagra biénnis grandiflora ( Ait.) Lindl.; Small, 
Bull. Torr. Club, 23:171. 1896. 
OEnothera grandiflora Ait. Hort. Kew, 2: 2. 
1789. 
Stouter. Leaves larger, thicker and broader; flowers 2'-4’ broad. Range nearly that of the 
species, more common southward. 
3. Onagra Oakesiana (A.Gray) Britton. 
Oakes’ Evening-Primrose. (Fig. 2580.) 
OEnothera biennis var. Oakesiana A, Gray, Man. 
Ed. 5,178. 1867. 
Onagra Oakesiana Britton, Mem. Torr. Club, 5: 
233. 1894 
Resembling the preceding species, usually 
annual, dull green, pubescent with appressed 
velvety hairs. Stem 1°-4° tall, mostly simple; 
leaves narrow, the basal narrowly oblanceolate, 
3/-10’ long, the cauline lanceolate or linear-lan- 
ceolate, all acute, distantly dentate, sessile or 
short-petioled; flowers yellow, nocturnal, 1/-1%4” 
broad; spikes 4’-20’ long; calyx villous, its tube 
about 1’ long, its segments linear-lanceolate, 
one-half as long as the tube; petals obovate, 
%4/-3(’ long; capsule linear-pyramidal, grad- 
ually narrowed to the summit, 11¢/-1 14 long, 4- 
sided, curved; seeds prismatic, about 1’ long, 
the faces reticulated. 
Shores of the St. Lawrence and along the Great 
Lakes, south to southern New York and Nebraska. 
Summer, 
8. OENOTHERA I. Sp. Pl. 346.1753. 
Usually low annual biennial or perennial caulescent herbs, with prostrate or erect stems. 
Leaves alternate, sinuate or pinnatifid. Flowers perfect, yellow, axillary, or sometimes in 
terminal spikes, nocturnal; buds erect. Calyx-tube elongated, sometimes filiform, terete; 
calyx-segments 4, finally reflexed, deciduous. Petals 4, spreading. Stamens 8, equal in 
length; filaments filiform; anthers linear. Ovary 4-celled, elongated; united styles filiform; 
stigma deeply 4-cleft; ovules numerous, in 2 rows, ascending. Capsules usually narrowly 
cylindric, sometimes slightly tapering, spreading or ascending, obtusely 4-angled, loculici- 
dal. Seeds numerous, in 2 rows, terete, crowned by a tubercle. [Greek, wine-scenting, the 
roots being once used for that purpose. ] 
About 20 species, in North America and western South America. 
