486 



ONAGRACEAE. 



[Vol.. II. 



2. Onagra biennis (L,.) Scop. 



Common Evening-Primrose. Night 



Willow-herb. (Fig. 2579.) 



OEnothera biennis L. Sp. PI. 346. 1753. 

 OE. muricata L. Syst. Ed. 12, 263. 1767. 



Erect, generally stout, annual or bien- 

 nial, simple and wand-like or branched, 

 i-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, i'-6' long; flowers spicate, 

 terminal, leafy-bracted, bright yellow, 

 opening in the evening, i / -2 / broad; 

 calyx-tube slender, much longer than the 

 ovary, the lobes linear, contiguous at the 

 base, reflexed ; capsules oblong, narrowed 

 above, erect, pubescent, fr / -i / long, 2#"- 

 3" thick, nearly terete; seeds angled. 



Usually in dry soil, Labrador to Florida, 

 west to the Rocky Mountains. Naturalized 

 in the Old World. June-Oct. 



Onagra biennis grandiflora ( Ait. ) I.indl. ; Small, 



Bull. Torr. Club, 23: 171. 1896. 

 OEnothera grandiflora Ait. I loft. Kew, a: 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, pnbescent with appressed 

 velvety hairs. Stem i-4 tall, mostly simple; 

 leaves narrow, the basal narrowly oblanceolate, 

 S'-lc/ long, the cauline lanceolate or linear-lan- 

 ceolate, all acute, distantly dentate, sessile or 

 short-petioled; flowers yellow, nocturnal, I'-iJ^' 

 broad; spikes 4 / -2o / long; calyx villous, its tube 

 about T/ long, its segments linear-lanceolate, 

 one-half as long as the tube; petals obovate, 

 %'-%' long; capsule linear-pyramidal, grad- 

 ually narrowed to the summit, i* f -ift f long, 4- 

 sided, curved; seeds prismatic, about \" long, 

 the faces reticulated. 



Shores of the St. Lawrence and along the Great 

 Lakes, south to southern New York and Nebraska. 

 Summer. 



8. OENOTHERA L> Sp. PI. 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. 



