REVISION OF EPILOBIUM. 75 
ARTIFICIAL KEY TO NORTH AMERICAN SPECIES. 
A, Stigma deeply 4-lobed or 4-cleft. 
1. Seeds not prominently papillate, mostly smooth. 
Flowers purple or pale, never yellow. 
Flowers very large, opening nearly flat. 
Seeds long and narrow, with persistent coma: pubes- 
cence not glandular. 
Leaves with very evident looped veins: bracts 
small: style pubescent at base... HZ. spicatum. 
Veins inconspicuous, rarely looped: bracts 
leafy: style glabrous........... EZ. latifolium. 
Seeds broad: ovary soft-glandular: bracts reduced, 
cooeee Ke rigidum. 
Flowers smaller, less open: seeds short and broad, with 
easily falling COMA. ...+-sseeeeeeeereeeeee He paniculatum. 
Flowers bright yellow, large but not opening widely: leaves 
broad, toothed, glabrouS...--sescccccscescscccesveds. luteum. 
2. Seeds papillately roughened under the microscope. 
Flowers cream-colored, smaller: leaves narrow, entire, can- 
CSCONE. cece ceeeee cece er csee cence ceeceeers Le SUfruticosum. 
Flowers purple or pale, never yellow. 
Hirsute or tomentose with long spreading white hairs, 
coeeee KL. hirsutum, 
Glabrous, canescent, or short glandular. 
Flowers very large and open: plants rather low, per- 
ennial, nearly simple above: leaves broad. 
Leaves acute at both ends, entire...........H. rigidum. 
Leaves rounded at base, repand-toothed, EZ. obcordatum. 
Flowers Jess open: plants tall, dichotomous or panicled: 
leaves elongated..... £. paniculatum and var. jucundum. 
E. exaltatum (cf. adenocaulon), EH. Oreganum (cf. glaberrimum), and 
another supposed hybrid, which is mentioned under Hornemanni, would 
be looked for under A, because of their stigmatic characters. 
B. Stigma entire or only notched: flowers never yellow. 
1, Seeds not prominently papillate, mostly smooth. 
Seeds broadly obovoid, very blunt: coma easily falling: leaves 
subpetioled, narrow, acute. 
Glabrous or glandular, dichotomous: leaves mostly veined, 
often incurved or folded along the midrib: seeds very 
large (1X2 MM)... cceecccccccccccesace E. paniculatum. 
Crisp-pubescent, simple or panicled: leaves mostly veinless: 
seeds half as large..........200 se covsceceee le. minutum. 
Seeds fusiform: coma more persistent. 
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