loasacejE. (loasa family.) 135 



» * # Stamens 4 ; petals rather persistent : carpels even, on the back ; leaves chieflij 

 scattered, or wanting on the flowering stems. 



5. ]n. am1>ig^UUIIl« Natt. Immersed leaves pinnatdy 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 ; fniit (minute) 

 smooth. — Var. 1. nItans : stems floating, prolonged. Var. 2. capillX- 

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

 lary. Var. 3. lim68um: small, rooting in the mud; leaves all linear, incised, 

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

 and southward, near the coast. July - Sept. 



6. M. teiielium, Bigelow. Flowering stems nearly leafless and scapeMke, 

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

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

 New York, New England, and northward. July. 



9. HIPPtTRIS, L. Make'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. Fniit nut-like, 1-celled, l-seedcd. — Peren- 

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

 the axils, perfect or polygamous. (Name from iWos, a horse, and ovpa, a tail.) 



1. II. Vlllguris, 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. LOASACE^. (Loasa Family.) 



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

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

 by the genus 



1. MK^TXtil.IA, Plum. (BAitT6NiA, 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 tenninal, solitary or 

 eymose-clustered. (Dedicated to C. Mentzd, 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 (7" - 10" broad), opening in sunslune ; petals wedge- 

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

 seeded. ® U — Prairies and plains, IlUnois and soutliwestward. 



