OUDER 52. ONAGRACE^E. 357 



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

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



9. PROSERPINA V CA, L. MERMAID WEED. (Lat. Proserpina, a 

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

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

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

 :alyx. 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, 

 X. Eng., Fla. and La. Rt. creeping. Ste. ascending at base, G 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 pinnatifid with linear segments. Fls. 

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

 a very hard, triangular nut. Jn., Jl. 



2 P. pectinacea Lam. Lvs. all 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, Vaill. WATER MILFOIL. (Gr. pvpiof, innu- 

 merable, 0yAAa, leaves.) Flowers 8 , or frequently Q ; 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. H submersed, aquatic 

 herbs. Submersed Ivs. parted into capillary segments. Upper fls. usu- 

 ally $ , middle ones g , lower ? . 



Stamens S. Carpels smooth and even. Leaves whorlod in Ss Nos. 1, 2 



Stamens 4. Carpels ridged on the back. Lvs. whorled in 4s anil Ds Nos. 3, 4 



Carpels smooth and even. Lvs. alternate or wanting .Nos. 5, 6 



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

 ments; fls. in terminal, nearly naked spikes; floral Ivs. 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 cf innumerable, 

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



2 M. verticillatum L. Lvs. in verticils of 3s, lower ones pinnattly parted into 

 opposite, capillary or setaceous segments; fls. in terminal, leafy spikes ; floral Ivs. 

 pectinate-pinnatifid, 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 tho upper part emerging. Fls. small, green, axillary, with 

 conspicuous floral Ivs. Sep. acute. Anth. oblong. Jl., Aug. 



3 M. heterophyllum MX. Lvs. in verticils of 5s, the lower ones pinnately 

 parted into capillary lobes ; spikes terminal, nearly naked ; floral li:s. cvate-lanceo~ 

 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. SUK! 

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

 nately divided. Petals somewhat persistent. Sepals minute. Braci lets serrulate. 

 Jn. Sept. 



4 M. scabratum MX. Lvs. pinnatifid in whorls of 4s and 5s; fls. verticillate, 

 axillary, upper fls. $ , with 4 stam., lower ones ? ; floral Ivs. linear, pectinately 

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

 Island (Robbins), S. and W. States. St. G to 12' high. Segm. of the Ivs. liuear- 

 capillary. 



5 M. tenellum Bw. Erect and almost leafless; floral Ivs. or brncts alternate, 

 minute, entire, obtuse; fls. Q ; petals linear; stam. 4; carp, smooth, not ridgecL 

 About the edges of poadg and rivers, Providence, R. I. (Olney), northern part of 



