488 EMPETRACE.E. (CROWBERRY FAMILY.) 



adjacent coast of Maine, alpine summits in N. Eng. and N. Y., L. Superior, 

 and northward. (Eu.) 



2. CO RE MA, Don. BROOM-CROWBERRY. 



Flowers dioecious or polygamous, collected in terminal heads, each in the 

 axil of a scaly bract, and with 5 or 6 thin and scarious imbricated bractlets, 

 but no proper calyx. Stamens 3, rarely 4, with long filaments. Style slen- 

 der, 3- (or rarely 4-5-) cleft; stigmas narrow, often toothed. Drupe small, 

 with 3 (rarely 4-5) nutlets. Seed, etc., as in the last. Diffusely much- 

 branched little shrubs, with scattered or nearly whorlc,d narrowly linear heath- 

 like leaves. (Name ic6pri[j.a, a broom, from the bushy aspect.) 



1. C. Conradii, Torr. Shrub 6' -2 high, diffusely branched, nearly- 

 smooth ; drupe very small, dry and juiceless when ripe. Sandy pine barrens 

 and dry rocky places, N. J. and L. Island (1), Shawaugunk Mts., N. Y., coast 

 of S. E. Mass, and Maine, to Newf. The sterile plant is handsome in flower, 

 on account of the tufted purple filaments and brown-purple anthers. 



ORDER 106. CERATOPHYLLACEyE. (HORNWORT FAMILY.) 



Aquatic herbs, with whorled finely dissected leaves, and minute axillary 

 and sessile monoecious flowers without floral envelopes, but with an 8- 12- 

 cleft involucre in place of a calyx, the fertile a simple \-celled ovary, with a 

 suspended orthotropous ovule, ,- seed fllled by a highly developed embryo 

 with a very short radicle, thick oval cotyledons, and a plumule consisting of 

 several nodes and leaves. Consists only of the genus 



1. CERATOPHYLLUM. L. HORNVVORT. 



Sterile flowers of 10-20 stamens, with large sessile anthers. Fruit an 

 achene, beaked with the slender persistent style. Herbs growing under 

 water, in ponds or slow-flowing streams ; the sessile leaves cut into thrice- 

 forked thread-like rigid divisions (whence the name from /ce'pas, a horn, and 

 <pv\\ov, leaf). 



1. C. demersum, L. Fruit smooth, marginless, beaked with a long 

 persistent style, and with a short spine or tubercle at the base on each side. 

 Var. ECHIN\TUM, Gray, has the fruit mostly larger (3" long), rough-pim- 

 pled on the sides, the narrowly winged margin spiny-toothed. Slow streams 

 and ponds, across the continent. (Eu., etc.) 



