108 ONAGRACEtE. 



Wet grounds. Arct. Amer. to Geor. W. to Oreffon. July, Aug. %. — Stem 

 1 — 3 feet high, much branched, often purplish. Flowers small, purplish, some 

 times nearly white. Colored WUlow Herb. 



3. E. palustre Linn. : stem terete, branched, somewhat hirsute ; leaves 

 lanceolate, rather acute, attenuate at base, nearly sessile, sparingly toothed 

 or entire, the lower ones opposite ; petals about twice the length of the 

 calyx ; stigma undivided ; capsule pubescent. E. rosmari folium Parsh. 

 E squamatum NiUt. 



Sphagnous swamps. Labrador to Penn. W. to Oregon. Aug., Sept. %. — 

 Stem 1 — 2 feet high, slender, at length much branched. Flowers pale purple 

 or white. Marsh Willow Herb. 



4. E. tetragonuvi Linti. : stem 4-sided, nearly smooth ; leaves opposite, 

 lanceolate-oblong, denticulate, lower ones sUghtly petioled ; petals emargi- 

 nate ; stigma clavate ; capsule pedicellate. 



Low grounds. Can. to Car. July. 'l\.. — Stem 2 feet higb, branched, smooth. 

 Flowers small, pale red, in terminal racemes. Perhaps not a native of the 

 Northern States. Square-stalked Willow Herb. 



5. E. molle Torr. : densely and softly pubescent ; stem terete, erect ; 

 leaves alternate and opposite, crowded, sessile, lanceolate or oblong-linear, 

 remotely denticulate or entire ; petals deeply emarginate, twice as long as 

 the calyx ; stigma large and thick ; capsule pedicellate. E. strictum MuM.. 



Sphagnous swamps. N. Y., N. J., and Penn. Aug., Sept. '2J.. — Stem 18 — ^20 

 inches high, simple or branched above. Flowers axillary in the upper part of 

 the stem, pale purple. Soft Willow Herb. 



6. E. alpinum Linn. : stem creeping at the base, usually marked with 

 2 pubescent lines ; leaves opposite, ovate or ovate-oblong, slightly petioled. 

 denticulate, smooth ; stigma entire ; capsule mostly pedicellate. 



Mountains. Essex county, N. Y. Torr. White Mountains, N. H. Big. N. 

 to Arct. Amer. July. '2J.. — Stem 6 — 10 inches high, slender, simple. Flowers 

 small, pale purple. Alpine Willow Herb. 



2. GAURA. Linn.—Ga.\ira.. 



(From the Greek yaposf superb ; on account of its showy spikes of flowers.) 



Calyx tubular, adnate to the ovary at base > segments 4, re- 

 flexed ; tube deciduous. Petals mostly 4-clawed, somewhat 

 unequal. Stamens usually 8. Fruit 4-angled, dry and inde- 

 hiscent, by abortion mostly 1 -celled, 1 — 4-seeded. Seeds 

 naked, 



G. biennis Linn. : stem herbaceous, erect, hairy, mostly purplish ; leaves 

 alternate, sessile, lanceolate, toothed ; flowers numerous, sessile, in terminal 

 spikes ; fruit roundish, slightly 4-angled, pubescent. 



Banks of streams. Can. to Geor. W. to 3Iiss. July, Aug. (^—Stem 2 — 5 

 feet high. Flowers dark rose-colored, sessile, in terminal spikes. 



Biennicd Gaura. 



3. CENOTHERA. Linn. — Evening Primrose. 



(Said to be derived from the Greek oivos, wine, and Bripa, hunting ; but the ap- 

 plication is imcertain.) 



Calyx with a long 4-sided or 8-ribbed deciduoufj tube ; seg- 



