EVENING-PRIMROSE FAMILY 585 



or white, purple-veined; style shorter than the stamens, glabrous; capsule 5-8 

 cm. long. Epilobium latifolium L. Wet places, especially along mountain 

 streams: Greenl. Que. S.D. Colo. Wash. Alaska. Subalp. Alp. Je-Au. 

 4. C. subdentatum Rydb. Stem 2-3 dm. high, finely puberulent; leaves 

 narrowly lance-linear, more or less distinctly denticulate, 24 cm. long, 3-8 mm. 

 wide, finely puberulent, the midvein strong, but the lateral ones obscure; sepals 

 lance-linear, 12 mm. long, purplish; petals oblanceolate, about 15 mm. long, 

 rose or white; style shorter than the stamens, glabrous; capsule 3-6 cm. long, 

 2 mm. thick. Banks: Alta. B.C. Subalp. 



2. EPILOBIUM (Gesn.) L. WILLOW-HERB, COTTON-WEED. 



Caulescent herbs, rarely shrubby. Leaves alternate or opposite, with often 

 toothed blades. Flowers perfect, racemose or spicate, or rarely solitary. Hy- 

 panthium prolonged beyond the ovary into an obconic short tube. Sepals and 

 petals 4, the latter often notched, purplish, pink or white, rarely yellow. Sta- 

 mens 8, not declined. Stigma club-shaped, subentire, slightly notched, or 

 rarely 4-lobed. Capsule elongate, subcylindric, slightly fusiform or clavate, 

 4-celled, 4-sided, loculicidal. Seeds with a tuft of hairs (coma) at the upper end. 



Petals purple, pink or white. 



Perennials; stigma entire or merely notched. 



Leaves oblong, oval, ovate, or lanceolate, usually dentate or denticulate. 



Plants with rosettes or turions: leaves ovate or lanceolate, usually broadest 

 below the middle, and distinctly denticulate or dentate (except some- 

 times in nos. 8, 9, and 16). 



Stem pubescent throughout; leaves also pubescent, at least when young. 

 Pubescence consisting of long silky hairs. 1. E. ursinum. 



Pubescence short and dense, crisp or glandular. 



Petals 7-8 mm. long. 2. E. Sandbergii. 



Petals 4-5 mm. long. 



Leaves ovate, permanently glandular, dark green. 



3. E. Palmeri. 

 Leaves lanceolate, glabrous in age, pale green. 



13. E. stramineum. 

 Stem glabrous below; leaves glabrous or nearly so. 



Flowers 7-8 mm. long; petals purple or dark pink; leaves ovate-lance- 

 olate. 



Leaves sessile or nearly so; innovations by turions. 

 Seeds without apiculations; coma sessile. 



Plant tall, 5-10 dm. high; leaves dark green, sharply dentate. 



4. E. glandulosum. 

 Plant low, 2-4 dm. high; leaves light green, more indistinctly 



denticulate. 5. E. ovatifolium. 



Seeds with a pale hyaline beak at the apex. 6. E. brevistylum. 

 Leaves short-petioled ; innovations by rosettes. 7. E. occidental. 

 Flowers 3-5 mm. long. 



Leaves all except the uppermost, short-petioled. 



Seeds pellucid-apiculate; leaves not very thin; pods strongly 



ascending or nearly erect. 

 Innovations by rosettes. 



Leaves narrowly lanceolate, pale green; corolla white. 



8. E. americanum. 

 Leaves broadly lanceolate, not pale; corolla usually pink. 



9. E. adenocaulon. 

 Innovations by turions. 10. E. latiusculum. 



Seeds not apiculate; leaves very thin; pods ascending-spreading. 



11. E. MacDougalii. 

 Leaves all sessile or only the very earliest sometimes short-petioled. 



Leaf-blades rounded at the base, broadly lanceolate to ovate. 

 Petals purple, 5-8 mm, long, leaf-blades usually ovate. 



5. E. ovatifoUum. 

 Petals white, 4 mm. long; leaf -blades lanceolate. 



12. E. rubescens. 

 Leaf-blades acute at the base. 



Petals white or rarely pale pink. 



Leaf-blades ample, ovate or broadly lanceolate. 



Plant tall, 3-6 dm. high; pod and inflorescence more 



or less glandular. 13. E. stramineum. 



Plant 1-2 dm. high; whole plant perfectly glabrous, ex- 

 cept the slightly crisp-hairy decurrent lines. 



14. E. saximontanum. 



Leaf-blades narrowly lanceolate, almost erect; plant slender, 

 1-3 dm high. 15. E. Drummondii. 



