840 EPILOBIACEAE 
em. broad : capsules narrowly oblong-conic, erect, pubescent, 18-25 mm. long, nearly terete. 
[ Oenothera biennis L.] P 
In dry or stony soil, Labrador to Florida west to the Mississippi Valley. Summer and fall.—A 
variety, O. biennis grandiflora ( Ait.) Lindl., is larger and stouter, has larger, thicker and broader leaf- 
blades and a corolla 5-8 cm. broad ; it is more common in the southern part of the range. 
2. Onagra Jamésii (T. & G.) Small. Stems stout, canescently strigillose, decumbent, 
1-4 m. long, more or less branched : leaf-blades narrowly oblong or lanceolate, 5-20 cm. long, 
often curved, acute, repandly denticulate, the lower ones narrowed into short petiole-like 
bases, the upper sessile or nearly so : hypanthium stout, 5-11 cm. long: sepals nearly linear, 
about half as long as the hypanthium : corolla showy, yellow, turning to rose: capsules 
tapering upward, 35-40 mm. long. [Oenothera Jamesii T. & G.] 
In dry soil, southern Utah to Texas and Arizona. Summer. 
8. OENOTHERA L. 
Caulescent annual biennial or perennial herbs, with depressed or erect stems. Leaves 
alternate : blades sinuate or pinnatifid. Flowers axillary, or sometimes in terminal spikes, 
nocturnal. Buds erect. Hypanthium filiform or slender. Sepals deciduous. Corolla yel- 
low. Ovary 4-celled, elongated. Ovules in 2 rows, ascending. Capsule usually narrowly 
cylindric, sometimes slightly tapering, spreading or ascending. Seeds terete, each crowned 
with a tubercle. EvENING PRIMROSE. 
Flowers axillary. 
Stems clothed with dense appressed or ascending hairs. 
Corolla 2-3 em. broad : species native along the Atlantic Coast. x 1. O. humifusa, 
Corolla 7-9 cm. broad : species native along the western Gulf Coast, occasion- Ms 
ally naturalized on the Atlantic Coast. 2. 0. Drummondii. 
Stems glabrous or rarely with spreading hairs. 3. O. laciniata. 
Flowers in a terminal bracted spike. 
Spike lax: bracts ovate: hypanthium villous. 4. O. heterophylla. 
Spike dense: bracts narrow: hypanthium silky-strigose. 5. O. rhombipetala. 
1. Oenothera humifiisa Nutt. Stems branched at the base, the branches spreading, 
decumbent or ascending, 2-5 dm. long, silky canescent : leaves various, the basal with ob- 
long-spatulate pinnatifid blades, the cauline with oblanceolate to lanceolate acute, undulate 
repand or toothed blades, 2-3.5 cm. long : flowers axillary : hypanthium 2-3 em. long : sepals 
about à as long as the hypanthium : corolla 2-3 cm. broad : capsules narrowly cylindric, 2-3 
em. long, somewhat curved upward : seeds 1.5-2 mm. long, striate. 
In drifting sand along the coast, New Jersey to Florida. Spring to fall. 
2. Oenothera Drummóndii Hook. Stems branched at the base, the branches de- 
cumbent, 2-7 cm. long, pubescent with appressed stiff-silky hairs: leaves various ; blades 
spatulate to lanceolate, or sometimes ovate or obovate towards the ends of the branches, 
1-4 cm. long, entire or distantly toothed: flowers axillary: hypanthium stout, 2-4 cm. 
long: sepals nearly linear, more than $ as long as the hypanthium : corolla 7-9 cm. broad : 
capsules cylindric, 2.5-4 cm. long, spreading, curved upward: seeds nearly 1.5 mm. 
long, pitted. 
On the coast of Texas. Spring to fall. 
3. Oenothera laciniàta Hill. Stems decumbent or ascending, sometimes branched, 
1-5 dm. tall, glabrous or sparingly hirsute : leaf-blades oval, lanceolate, oblong, or oblan- 
ceolate to spatulate at the base of the plant, 2.5-5 cm. long, acute or obtusish at the apex, 
sinuate-dentate or often pinnatifid : flowers axillary: hypanthium 3-4 cm. long : sepals re- 
flexed : corolla 12-36 mm. broad : capsules linear-cylindric, 2.5-3.5 cm. long, more or less 
pubescent : seeds 1.2-1.5 mm. long, strongly pitted. [Oenothera sinuata L. ] 
In dry sandy soil, southern Vermont to New Jersey, Nebraska, Florida, Texas and Mexico, extend, 
ing into South America. Spring and summer.—0. laciniata grándis Britton, with more prominen "d 
toothed leaf-blades and corollas 5-7 em. wide, ranges from Missouri to Kansas and Texas, an 3 d 
laciniata Mexicana (Spach.) Small, with shaggy hirsute stems, leaves and capsules, occurs in Texas & 
northern Mexico. 
. 4. Oenothera heterophylla Spach. Stems relatively slender, erect, 4-9 dm. tall, 
rather sparingly appressed-pubescent : leaf-blades narrowly oblong to lanceolate, sometimes 
narrowly lanceolate or spatulate on the lower part of the stem, 1-6 cm. long, acute, un p 
late or remotely and shallowly toothed, sessile and slightly clasping on the upper " s 
the stem : corolla 2-4 em. broad : sepals sparingly and loosely glandular-pubescent : pe 
obovoid, 1-2 em. long: capsules columnar, but slightly tapering to the apex, curve, 
1.5-2 em. long, loosely pubescent : seeds fully 1 mm. long. 
In sandy soil, sometimes in woods, Florida to Texas. Spring and summer. 
5. Oenothera rhombipétala Nutt. Stems relatively stout, erect, 6-12 oe wage 
finely and densely appressed-pubescent : leaf-blades lanceolate to linear-lanceola 
