ILLECEBRACE^E. 51 



the calyx. C. kirsutum Muhl. C. connatum Seek, Dot. 1st. Ed. C. semi- 

 decandrum Walt. 



Fields and hills. Can. to Geor. May Aug. .Stem 610 inches high. 

 Flowers white. Introduced from Europe. Common Mouse-ear Chickweed. 



2. C. viscosum Linn. : hairy and somewhat viscid, deep green ; stems 

 numerous, erect ; leaves lanceolate-oblong; flowers subpaniculate, shorter 

 than their pedicels ; capsule somewhat incurved, terete, as long again as 

 the calyx. C. semidecandrum Linn. 



Fields and road sides. Can. to Louis. May Aug. 7J.. Stems 612 inches 

 high. Leaves rather obtuse. Petals white, obovate, a little longer than the 

 calyx. Introduced from Europe. Clammy Mouse-ear Chickweed. 



3. C. arvense Linn. : stems ascending ; leaves linear-lanceolate, obtuse ; 

 more or less hairy, especially at base ; flowers few, terminal ; peduncles de- 

 flexed, pubescent ; petals twice as long as the calyx ; capsule oblong-cylin- 

 dric, scarcely longer than the calyx. C. tenuifolium Pursh. C. Pennsyl- 

 vanicum Horn. 



Rocky places. Can. to Geor. W. to the Rocky Mountains. May Aug. 

 11-. Root creeping. Stems 4 8 inches long, ascending, slender, somewhat 

 cespitose. Leaves crowded at the base of the stem, short, ciliate at base, 

 Flov>ers large, 2 or 3 on terminal pedicels. Petals deeply cleft, white, twice 

 as long as the calyx. Field Chickweed. 



4. C. oblongifoliumTorr. : stems erect or declined, villous; leaves oblong- 

 lanceolate, mostly obtuse ; flowers numerous ; peduncles viscid ; petals obo- 

 vate, 2-cleft, twice the length of the oblong obtuse sepals ; capsule cylindrical, 

 about twice as long as the calyx. C. pubescens Goldie. C. viUosum. Muhl. 



Rocky places. Can. to Penn. ; rather rare. May, June. 1J-. Stems 6 12 

 inches high, rather stout, very villous, tomentose at and below the nodes. 

 Flowers larger than in C. arvense, 7 15 in a cyme. 



Oblong-leaved Chickweed. 



5. C. nutans Raf. : viscid and pubescent ; stem erect, straight, deeply 

 striate; leaves elongated, distant, lanceolate-linear; panicle much elongated, 

 divaricate, many-flowered, with long filiform pedicels ; petals oblong, bifid 

 at the tip, longer than the calyx ; capsule nodding, twice as long as the 

 calyx. C. glutinosum Nutt. C. longepedunculatum Muhl. 



Moist grounds. Hudson's Bay to Louis. W. to Oregon. June. (1). Stem 

 8 12 inches high, very viscid and covered with a woolly pubescence. Lower 

 leaves oblong-spatulate, acute. Flowers terminal, in a loose dichotomous pan- 

 icle. Nodding Chickweed. 



ORDER XIX. ILLECEBRACE^E. KNOTWORTS. 



Sepals 5, seldom 3 or 4, distinct or more or less cohering. 

 Petals minute, inserted upon the calyx between the lobes, oc- 

 casionally wanting. Stamens as many as the sepals and oppo- 

 site to them, or fewer by abortion. Ovary superior ; styles 2 5, 

 distinct or partially combined. Fruit small, dry, 1 -celled, either 

 indehiscent or opening with 3 valves. Seeds solitary or nume- 

 rous, with mealy albumen. Herbaceous or half shrubby plants, 



