108 ONAGRACE^E. 



Wet grounds. Arct. Araer. to Geor. W. to Oregon. July, Aug. 7L Stem 

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

 times nearly white. Colored Willow 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. rosmarifolium Pursh. 

 E sjuama'um Nutt. 



Sphagnous swamps. Labrador to Penn. W. to Oregon. Aug., Sept. 1|-. 

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

 or white. Marsh Willow Herb. 



4. E. tetragonum Linn. : stem 4-sided, nearly smooth ; leaves opposite, 

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

 nate ; stigma clavate ; capsule pedicellate. 



Low grounds. Can. to Car. July, '2J-. Stem 2 feet high, branched, smooth. 

 Flowsrs 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 MM. 



Sphagnous swamps. N. Y., N. J., and Penn. Aug., Sept. Tj.. 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. alpmum 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. %. Stem 6 10 inches high, slender, simple. Flowers 

 small, pale purple. Alpine Willow Herb. 



2. GAURA. Linn. Gaura. 



(From the Greek yapos, 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 Miss. July, Aug. (g). Stem 2 5 

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



Biennial Gaura. 



3. CENOTHERA. Linn. Evening Primrose. 



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

 plication is uncertain.) 



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



