MEMOIRS FROM THE DEPARTMENT OF I?OTANY OF COLUMBIA COLLEGE. 



19 



Somewhat woody, annual or perennial plants ; leaves cauline, often reduced to 

 foliaeeous bracts above ; ocreae membranous and usually hyaline, fiinnelform, oblique, 

 two-parted, at length lacerate ; inflorescence consisting of axillary clusters, either 

 widely separated or crowded into a terminal raceme; flowers subtended by ocreae ; 

 calyx five-parted ; stamens mostly eight ; style three-parted or wanting and stigma 

 three-cleft ; achene triquetrous, included Or exserted ; cotyledons incumbent. 



Slender, wiry, brittle annual or perennial plants ; leaves narrow and reduced to 

 bracts above, with two lateral nerves ; ocreae funnelform, membranous, early con- 

 spicuously lacerate or rarely two-parted; inflorescence spicate, the nodes of the 

 shortened branches and branchlets each bearing a single flower ; calyx five-cleft or 

 five-parted ; stamens eight ; style three-parted ; achene triquetrous ; cotyledons 

 incumbent.. 



Annual or perennial, more pr less twining plants; leaves usually cordate or 

 truncate ; ocreae membranous, funnelform, oblique, naked at the summit, sometimes 

 fringed at the base ; inflorescence consisting of loose axillary or terminal clusters, 

 racemes or panicled racemes ; flowers subtended by ocreae ; calyx five-parted, the 

 outer segments keeled or winged; stamens eight ; style three-parted or wanting, the 

 stigma three-cleft ; achene triquetrous ; cotyledons accumbent. 



Annual or perennial plants,, climbing by recurved prickles; leaves mostly has- 

 tate or sagittate ; oci'eae rnembranous, funnelform, oblique, mostly naked ; inflores- 

 cence consisting of axillary and terminal racemes or capitate clusters ; flowers sub- 

 tended by ocreolae ; calyx five-parted, rarely four-parted ; stamens eight ; style two- 

 parted or three-parted ; achene lenticular or triquetrous ; cotyledons accumbent. 



6. AVICULARIA. 



T. DORAVIA. 



8. TiNIARIA. 



9. ECHINOCAULON. 



I. SUBGENUS BISTORTA. 



Herbaceous alpine or subalpine plants, mostly glabrous, bright green, perennial by a 

 more or less thickened globose or elongated creeping or horizontal rootstock. Rootstock 

 somewhat fleshy, covered with the chaffy remains of modified ocreae. Stem simple, 

 terete or channeled, slender, strict, somewhat fleshy, usually straw-colored. Leaves 

 radical and cauline, the former long-petioled, the latter short-petioled or sessile, flat or 

 more or less, revolute, never punctate. Ocreae cylindric, membranous, hyaline, never 

 ciliate, clasping the stem, opened obliquely at the summit. Inflorescence consisting of a 

 single, terminal, spicate raceme. Raceme varying from nearly globose to oblong, densely 

 flowered, sometimes bearing bulblets at the base. Ocreolae bractrlike, hyaline, membran- 

 ous, entire or toothed. Pedicels slender, articulated at the base of the calyx. Calyx 

 five-parted, colored, not glandular-punctate nor much enlarged in fruit. Stamens eight, 

 rarely nine, exserted. Style three-parted, rarely two-parted, exserted. Stigmas minute 

 and inconspicuous. Achene triquetrous, rarely lenticular, brown, smooth or granular, 

 invested by the calyx. Albumen horny. Cotyledons accumbent. 



