528 HALORAGEiE. Proserpinaca. 



calyx, or sometimes fewer, inserted with the petals into the summit 

 of the calyx. Ovary coherent with the calyx, 1-4-cellecl, with a 

 soHtary pendulous ovule in each cell : style none : stif^mas equal 

 in number with the cells of the ovary, papillose or penicillate, dis- 

 tinct. Fruit dry and indehiscent, membranous or bony, 1-4-celled. 

 Seed anatropous, with a thin fleshy albumen. Embryo straight : 

 radicle long and tapering : cotyledons minute. — Herbs or sudVuticose 

 plants, growing in water or wet places. Leaves alternate, opposite, 

 or verticillate. Flowers very small, axillary, sessile, occasionally 

 moncEcious or dioecious. 



13. PROSERPINACA. Linn. ; Lam. ill. t. 50 ; Juss. in ann. mus. 3- 



J}. 320, t. 30,/. 1. 



Tube of the calyx 3-sided ; the limb 3-parted. Petals none. Stamens 3. 

 Stigmas oblong, papillose. Fruit bony, triquetrous, 3-celled. — Perennial 

 aquatic herbs ; the stems creeping at the base. Leaves alternate, serrate or 

 pectinately parted. Flowers axillary (perfect), solitary or 3-4 together. 

 Parts of the flower rarely quaternary. 



--^^ 1. P. palustris {hinn.) : leaves lanceolate or linear, sharply serrate ; the 

 lowermost (when submersed) pectinately incised or pinnatitid ; fruit acutely 

 triquetrous.— Z-i««. / act. Ups. 1741, p. 81 ; Michx. ! ft. 1. p. 76 ; Ell. sk. 

 1. p. 181 ; Tan: ! fl. 1. ^?. 161 ; DC. ! prodr. 3. p. 67. Trixis palustris, 

 Gcertn. fruct. 1. p. 115, t. 24. 



Swamps, ponds, and ditches (Canada, PursJi), Vermont ! and Massachu- 

 setts ! to Florida ! and Arkansas ! June-Aug. — Stems 6-20 inches in 

 length. Stigmas (purplish) cylindrical, obtuse. 



^-A'2. P. pectinacea (Lam.): leaves all pectinate; the segments linear- 

 subulate; angles of the fruit rather obtuse. — Lam. ill. t. 50, /. 1 ; Pursh, 

 fl. 1. p. 92 ;^Ell. I. c. ; Ton: ! fl. 1. p. 162 ; DC. ! I. c. P. palustris /?. 

 Michx. ! I. c. 



Sandy swamps, Plymouth, Massachusetts, Mr. OaJces ! Mr. TucJcerman ! 

 New Bedford, Mr. T. A. Greene! and New Jersey ! to Florida! August. 

 (May in the Southern States.) — Stigmas attenuate above. Plant smaller 

 than the preceding species ; the fruit smaller, rather than larger as stated by 

 Elliott and DeCandoUe. The latter author has inadvertently described the 

 leaves as opposite in the character of the genus. 



14. MYRIOPHYLLUM. Vaill. ; Linn. ; Gcertn. Jr. t. 68 ; Lam. ill. 



t. 775 ,• DC. prodr. 3. p. 68. 



Flowers monoecious or frequently perfect. Calyx 4-parted in the sterile 

 flowers, 4-toothed in the pistillate and perfect flowers. Petals 4, frequently 

 inconspicuous or wanting. Stamens 4 or 8, rarely 6 ? Ovary 4-celled : 

 stigmas oblong or linear, often compressed, penicillate or papillose along the 

 inner surface, recurved. Fruit of 4 nut-like indehiscent carpels, cohering 

 by their inner angles, and enclosed in the adherent tube of the calyx, apicu- 

 late with the base of the stigmas. — Aquatic usually submersed perennial 

 plants, the upper part emersed while flowering. Leaves verticillate, some- 



