LOASACE^E. {JLOASA FAMILY.) 135 



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

 scattered, or wanting on the flowering stems. 



5. in. mtlhi^lllim, Nutt. 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. NATANS : stems floating, prolonged. Var. 2. CAPILL\ 

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

 lary. Var. 3. LIMOSUM: small, rooting in the mud ; leaves all linear, incise|| 

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

 and southward, near the coast. July - Sept. 



6. M. tClielluill, Bigelow. Flowering stems nearly leafless and scape-like, 

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

 small, entire; flowers alternate, monoecious; fruit smooth. Borders of ponds, N. 

 Now York, New England, and northward. July. 



9. IIIPPIJRIS, L. MARE'S-TAIL. 



Calyx entire. Petals none. Stamen 1, 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-celle.d, 1-sceded. Peren- 

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

 the axils, perfect or polygamous. (Name from ITTTTOS, a horse, and ovpd, a tail.) 



I. Iff. Vlilg&ris, L. Leaves in whorls of 8 or 12, linear, acute. Por.ds 

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

 2 high. Flowers very inconspicuous. (Eu.) 



ORDER 44. L,OASACE^E. (LOASA FAMILY.) 



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

 }..ff'nt to a \-cellcd ovary with 2 or 3 parietal placentas: represented only 

 by the genus 



1. 9IENTZEL.IA, Plum. (BARTOXIA, 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 m- 

 detinitc, rarely few, inserted with the petals on the .throat of the calyx. Styk'S 

 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 

 C} mose-clustcred. (Dedicated to C. Mentzel, an early German botanist.) 



1 RI. OljgO$priaBH, Nutt. Rough and adhesive (1 -3 high), much 

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

 or angled ; flowers yellow (7 M - 10" broad), opening in sunshine ; petals wed go- 

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

 seeded. (J) U Prairies and plains, Illinois and southwestward. 



