ONAGRACEAE. 657 



flowers usually nodding at first; seeds abruptly short- beaked, about I mm. long, 

 papillose. In moist grounds. N. B. to Ore., south to Mass., Penn., Iowa, Utah 

 and Cal. July-Sept. 



10. Epilobium Hornemanni Reichenb. HORNEMANN'S WILLOW-HERB. 

 (I. F. f. 2577.) Erect, 1.5-3 dm. high, simple or nearly so, slightly pubescent 

 above. Leaves short-petioled, ovate or elliptic, mostly broadly obtuse at the apex, 

 rather remotely denticulate, 1.2-3 cm. long; flowers few, purple or violet, 6-7 mm. 

 broad; stigma entire; capsules 2. 5-6 cm. long, nearly glabrous, slender-pedicelled; 

 seeds about I mm. long, papillose, nearly beakless. Moist places, White Mts. to 

 Lab., west to Wis. and Br. Col., south in the Rocky Mts. to Colo., and to Cal. 

 Also in Europe. Summer. 



7. O'NAGRA Adans. 



Annual or biennial herbs, with mostly erect stems. Leaves alternate, undulate 

 or toothed; buds erect. Flowers yellow, nocturnal, in terminal spikes. Calyx- 

 tube elongated. Ovary 4-celled ; ovules in 2 or more rows, horizontal. Capsule 

 4-angled, more or less tapering, opening loculicidally. Seeds prismatic-angled. 

 [Greek, the wild ass, said to refer to the similarity of its leaves to the ears of that 

 animal.] About 12 species, chiefly North American. 



Flowers relatively small; petals narrow, 2-4 mm. wide. I. O. cm data. 



Flowers relatively large; petals broad, 12-50 mm. wide. 



Capsules 2-3 cm. long or shorter, abruptly narrowed at the apex; pubescence not 

 velvety. 

 Stems slightly hispid; capsules glabrous or sparingly pubescent. 



2. O. biennis. 



Stems very strigose; capsules copiously pubescent. 3. O. strigosa. 



Capsules 3 cm. long or longer, gradually narrowed to the apex; pubescence velvety. 



4. O. Oakesiana. 



1. Onagra cruciata (Nutt.) Small. SMALL-FLOWERED EVENING-PRIMROSE. 

 (I. F. f. 2578.) Glabrous or sparingly villous. Stem erect, 6-12 dm. tall, usually 

 simple; leaves narrowly oblong or oblanceolate (the upper ones often lanceolate), 

 4-10 cm. long, acute, serrate-denticulate, the lower ones slender-petioled, the upper- 

 most nearly sessile; spikes 1-3 dm. long, leafy-bracted ; calyx-tube slender, 8-25 

 mm. long, sparingly villous; petals linear, 10-12 mm., long, acutish; capsules 

 2.5-2.8 cm. long, gradually narrowed from the base. Me. to N. Y. and Mass. 

 Aug. -Oct. 



2. Onagra biennis (L.) Scop. COMMON EVENING- PRIMROSE. NIGHT WIL- 

 LOW-HERB. (I. F. f. 2579.) Erect, generally stout, 3-25 dm. high, more or less 

 hirsute pubescent. Leaves lanceolate, acute or acuminate, sessile or the lower pe- 

 tioled, repand-denticulate, 2.5-15 cm. long; flowers spicate, leafy-bracted, bright 

 yellow, 2.5-5 cm - broad; calyx-tube slender, much longer than the ovary; cap- 

 sules oblong, narrowed above, erect, pubescent, 18-25 mm - l n g> nearly terete; 

 seeds nearly 2 mm. long. Usually in dry soil, Lab. to Fla., west to the Missis- 

 sippi Valley. Nat. in the Old World. June-Oct. 



Onagra biennis grandifl6ra (Ait.) Lindl. Stouter. Leaves larger, thicker and 

 broader; flowers 5-10 cm. broad. Range nearly that of the species; common southward. 



3. Onagra strigosa Rydb. STRIGOSE EVENING- PRIMROSE. Strigose and 

 somewhat villous above with grayish hairs, 4-10 cm. high. Leaves various, the 

 basal obovate or spatulate, obtuse; stem-leaves oblanceolate to lanceolate, 5-10 cm. 

 long or the upper shorter, acute, undulate; spike leafy-bracted, many-flowered; 

 calyx-segments with short free tips ; corollas pure yellow, 3-4. 5 cm. broad ; capsules 

 2.5-3 cm. long. In rich soil, S. Dak. and Mont, to Neb. Summer. Nat. about 

 eastern seaports. 



4. Onagra Oakesiana (A. Gray) Britton. OAKES' EVENING-PRIMROSE. 

 (I. F.f. 2580.) Resembling the next preceding species, dull green, pubescent with 

 appressed velvety hairs. Stem 3-12 dm. tall, often simple; leaves narrow, the 

 basal narrowly oblanceolate, 7.5-25 cm. long, the cauline lanceolate or linear-lan- 

 ceolate, all acute, distantly dentate; flowers 2.5-3.3 cm. broad; calyx-tube about 

 2.5 cm. long; capsule linear-pyramidal, gradually narrowed to the summit, 3- 



