A Revision of the Genus Clematis of the United States. 119 
Section I.—ATRAGENE.—Some of the outer filaments passing into 
small petals ; peduncles bearing single large flowers, the sepals spread- 
ing. 
1. C. VERTICILLARIS, DC.—W oody-stemmed climber, almost glab- 
rous; leaves trifoliate, with slender common and partial petioles; leaf- 
lets ovate or slightly heart-shaped, pointed, entire, or on sterile stems, 
1-3 toothed or lobed; flowers bluish purple (2’ to 3’ across); tails of 
the fruit plumose.* 
2. C. atpina, Mill.—A trailing, woody-stemmed plant, 6’ high, glab- 
rous but for a few scattered hairs; leaves biternately divided; seg- 
ments ovate or oblong, lanceolate, acuminate, frequently 3-lobed, irreg- 
ularly toothed; sepals 4, lance ovate, purplish blue.+ 
Var. OcHotensis, Gray.—With linear antheriferous petals.{ This is 
the form commonly found in the Rocky mountains, and differs from 
C. alpina and C. Siberica, only in the development of the petals. 
SEctTIoN I].—CLeMatTIs proper.— Petals entirely wanting. 
(1) Flowers solitary, pedunculate. 
a.—Stems erect, simple or branching. 
~ Leaves divided. 
3. C. Batpwini, Torr. & Gray.—Erect, 1°-14° high, simple or a 
little branching, slender, slightly pubescent; leaves varying from oblong 
to linear lanceolate, entire, or 3-cleft or lobed, lobes linear, often 
slightly laciniate, sometimes quite simple, 4’ to 6” wide, narrowed 
at base into a short petiole; peduncle terminal, 8’ to 10’ long, one 
flowered; flower cylindrical-campanulate; sepals purplish externally, 
yellowish within; tails of carpels 2’ to 3’ long, very plumose.§ 
4, C. Douexasit, Hooker.—‘ Stem herbaceous, 1° to 2° high, simple, 
one flowered ; leaves 2-3 pinnatified (or the lower ones more simple), 
the segments linear or linear lanceolate, both stem and leaves more or 
less hairy ; flower nodding, the naked peduncle erect and elongated in 
fruit ; sepals thick, woolly at the apex, more or less spreading, deep 
brownish purple, paler externally.” | | 
5. C. Scorru, Porter.—‘ More or less villous, with soft-spreading 
* Gray’s Manual, p 35. 
+ Watson, Bot. Nev. & Utah (vol. v., King’s Sur.) p. 3, and Porter & Coulter, Fl. Colo- 
rado, p. 1. 
t Watson, Jbid, p. 4 
@ Torrey & Gray, El. vol,:i., p. 8. || Watson, J. ¢., p- 3. 
