Okder 52.— ONAGRACEA 367 



1 to 2' long, § as wide, acute or acuminate, with small, remote teeth, pale green 

 and shining. Fls. white, ^rarely reddish, minute, in terminal racemes. Jl. 



9. PROSERPINA'CA, L. Mermaid Weed. (Lat. Proserpina, a 

 Roman goddess ; from some fancied resemblance.) Calyx tube ad- 

 herent to the ovary, 3-sided, limb 3-parted ; petals none ; stamens 3 ; 

 stigmas 3 ; fruit 3-angled, 3-celled, bony, crowned with the permanent 

 calyx. — if Aquatic. Lvs. alternate. 



1 P. palustris L. Lvs. linear-lanceolate, sharply serrate above the water, those 

 below (if any) pinnatifld. — Ditches, swamps and ponds, often partly submerged, 

 N. Eng., Fla. and La. Et. creeping. Sts. ascending at base, 6 to 20' high, 

 striate, roundish. Lvs. 10 to 15" by 2 to 3", acute at each end, lower ones on 

 short petioles and, if growing in water pinnatifld with linear segments. Fls. 

 greenish, sessile, 1 to 3 together, in the axils of the upper leaves, succeeded by 

 a very hard, triangular nut. Jn., JL 



2 P. pectinacea Lam. Lvs. aU pectinate, with linear-subulate segm. ; fr. obtusely 

 3-angled. — Sandy swamps, in Mass. (rare) S. to Fla. St. 5 to 10' high, ascending 

 at base from long, creeping roots. Lvs. all finely and regularly divided into very 

 narrow segments. Sty. ; stig. attenuate above. Fr. rather smaller (less than 

 1" diam.) than in P. palustris, rugous when mature. JL, Aug. 



10. MYRIOPHYL'LUM, VaiU. Watek Milfoil. (Gr. fivptog, innu- 

 merable, (jivXXa, leaves.) Flowers 8 , or frequently ^ ; calyx 4-toothed 

 in the ^ and ¥ flowers, 4-parted in the $ ; petals 4, often inconspicu- 

 ous or none ; stamens 4 to 8 ; stigmas 4, pubescent, sessile ; fruit of 4, 

 nut-like carpels, cohering by their inner angles. — 'U submersed, aquatic 

 herbs. Submersed lvs. parted into capillary segments. Tipper fls. usu- 

 ally $ , middle ones ^ , lower ¥ . 



8 Stamens 8, Carpels smootli and even. Leaves whorled in Ss Nos. 1, 2 



§ Stamens 4. — Carpels ridgetl on the back. Lvs. whorled in 4s and 5s Nos. 8, 4 



— Cavpels smooth and even. Lvs. altern.ite or wanting Nos. 5, 6 



1 M. spic^tum L. Lvs. in verticils of 3s, all pinnately parted into capillary seg- 

 ments; fls. in terminal, nearly naked spikes; floral lvs. or bracts, ovate, entire, 

 shorter than the fls., lowest ones subserrate and larger ; petals broadly ovate ; 

 stam. 8 ; carp, smooth. — ^N. Eng. to Ark., in deep water, the fls. only rising above 

 the surface. St. slender, branched, very long. Lvs. composed of innumerable, 

 hair-hke segments, always submerged. Fls. greenish, sessile. Jl., Aug. 



2 M. vertioillatviin L. Lvs. in verticils of 3s, lower ones pinnately parted into 

 opposite, capillary or setaceous segments ; fls. in terminal, leafy spikes ; flxn-al lvs. 

 pecti/nate-pimnaiifld, much longer than the fls. ; petals oblong-obovate ; stam. 8 ; 

 carp, smooth. In stagnant water. Can. to Fla,, "W. to Or. St. long, less slender 

 than in the last, only the upper part emerging. Fls. small, green, axillary, with 

 conspicuous floral lvs. Sep. acute. Anth. oblong. JL, Aug. 



3 M. heteroph^Uum Mx. Lvs. in verticils of 5s, the lower ones pinnately 

 parted into capillary lobes ; spikes terminal, nearly naked ; flxyral his. ovate-kmceo- 

 late, serrate, longer than the fls., crowded ; petals oblong ; stam. 4 to 6 ; carp, 

 scabrous, with 2 slight ridges on the back. — In sluggish water. Can. to Fla. and 

 Tex., rare. St. thick, branching. LvS. very various, lowest floral ones pecti- 

 nately divided. Petals somewhat persistent. Sepals minute. Bractlets serrulate. 

 Jn. — Sept. 



4 M. soabratum Mx. Lvs. pinnatifid in whorls of 4s and 5s ; fls. verticillate, 

 axillary, upper fls. $ , vntb. 4 stam., lower ones S ; floral lvs. linear, peciinately 

 toothed; fr. 8-angled, the ridges tuberculate. — Plymouth, Mass. (Oakes), Block 

 Island (Bobbins), S. and "W. States. St. 6 to 12' high. Segm. of the lvs. linear- 

 capiHary. 



5 M. ten^llum Bw. Srect and almost leafless; floral lvs. or bracta alternate, 

 minute, entire, obtuse; fls. 8 I petals linear; stam. 4; carp, smooth, not ridged. — 

 About the edges of ponds and rivers. Providence, E. I. (Olney), northern part of 



