LOASACEJE. (LOASA FAMILY.) 135 



* * # Stamens 4 : petals rather persistent : carpels even on the buck: leaves chiefly 

 scattered, or wUnting on the flowering stems. 



5. UI. million u He, Nntt. Immersed leaves pinnately parted into about 



10 very delicate capillary divisions ; the emerging ones pectinate, or the upper floral 

 linear and sparingly toothed or entire ; flowers mostly perfect; fruit (minute) 

 smooth. — Var. 1. xataxs : steins floating-, prolonged. Var. 2. CAi'iLiA- 

 ceum : stems floating, long; and very slender ; leaves all immersed and capil- 

 lary. Var. 3. limosuji: small, rooting in the mud ; leaves all linear, incised, 

 toothed, or entire. — Ponds and ditches, Massachusetts to New Jersey, lVnn., 

 and southward, near the coast. July - Sept. 



6. ]?I. teiielltlllB, Bigelow. I g stems nearly leafless and scape-like, 

 (3' -10' high), erect, simple; the sterile shoots creeping and tufted; bracts 

 small, entire; flowers alternate, moncecious ; fruit smooth. — Borders of ponds, X. 

 New York, New England, and northward. July. ' 



9. HlPPtEIS, L. Make's-tail. 



Calyx entire. Petals none. Stamen I, inserted on the edge of the calyx. 

 Style single, thread-shaped, stigmatic down one side, received in the groove be- 

 tween the lobes of the large anther. Fruit nut-like, 1-cclled, l-seeded. — Peren- 

 nial aquatics, with simple entire leaves in whorls, and minute flowers sessile in 

 the axils, perfect or polygamous. (Name from tirnos, a horsi , and ovpd, a tail.) 



1 211. vulgaris, L. Leaves in whorls of 8 or 12, linear, acute. — Ponds 

 and springs, New York to Kentucky and northward: rare. Stems simple, 1°- 

 2° high. Flowers very inconspicuous. (Eu.) 



Order 44. EOASACE/E. (Loasa Family.) 



Herbs, with a rough or stinging pubescence, no stipules, the calyx-lube ad- 

 herent to a 1-celled ovary with 2 or 3 parietal placentce : — represented only 

 by the genus 



1. 1HENTZELIA, Plum. (Bart6nia, Nutt.) 



Calyx-tube cylindrical or club-shaped ; the limb 5-parted, persistent. Petals 

 5 or 10, regular, spreading, flat, convolute in the bud, deciduous. Stamens in- 

 definite, rarely few, inserted with the petals on the throat of the calyx. Styles 

 3, more or less united into one : stigmas terminal, minute. Pod at length dry 

 and opening irregularly, few - many-seeded. Seeds flat, anatropous, with little 

 albumen. — Stems erect. Leaves alternate. Flowers terminal, solitary or 

 cjTnose-clustered. (Dedicated to C. Mentzel, an early German botanist.) 



1 M. Oligosperma, Nutt. Rough and adhesive (l°-3° high), much 

 branched, the brittle branches spreading; leaves ovate and oblong, cut-toothed 

 or angled ; flowers yellow ("'■'- 10" broad), opening in sunshine ; petals wedge- 

 oblong, pointed ; stamens 20 or more : filaments filiform : pod small about -9- 

 seeded. (J) 1], — Prairies and plains, Illinois and soudiwestward. 



