2 MONANDRIA MONOGYNIA. [CI. 1. 



4. S. fruticosa, 35. 2467. (Shrubby J.) Stem woody, ascending ; 

 joints and interstices cylindrical. Spikes nearly sessile, cylindri- 

 cal, obtuse. 

 Sea-shore,rare.2f.8,9. Woody, slender. Stigm.2. Avar, of S.r&d.? 



2. HIPPuRIS. Mare's-tail. 



1. H. vulgaris, 11. 763. (Common M.) Leaves linear, many in each 

 whorl. 

 Ditches and pools. %. 5. \.f. erect, simple. Fl. axill. solit. sessile. 



3. ZOSTeRA. Grass-wrack. 



1. Z. marina, 7. 467. (Common G.) Leaves entire, obscurely three- 

 ribbed. Stem slightly compressed 

 Salt water. If. . 8, 9. Leaves long, grassy. Spadix green. 



4. CHiRA. Chara. 



1. C. vulgaris, 5. 336. (Common C.) Striated, without prickles. 



Whorled branches tapering, with internal partitions. Bracteas 

 four together. 

 Muddy ditches. . 7. Immersed, generally incrusted with earth. 

 *1. C. Hedwigii, Suppl. 2762. (Hedwig's C.) Smooth, even, some- 

 what flexible. Branchlets articulated. Bracteas about equal to 

 the ovate fruit. 

 Pools, rare. . 6. Bracteas longer than in C. vulg. 

 **1. C. dspera, Suppl. 2738. (Rough C.) opaque, brittle, obscurely 

 striated, clothed with patent spinules. Whorled branches subu- 

 late ; fertile ones with many short bracteas accompanying the 

 fruit, varying in length. 

 Pools, rare. 0. 6. 7. Slender, opaque, very prickly. 



2. C. hispida, 7. 463. (Prickly C.) Furrowed. Whorled branches 



tapering, with internal partitions. Bracteas whorled. Prickles 

 on the stem bristly, deflexed. 

 Ditches and pools. ©. 7, 8. Incrusted like C. vulg., but prickly. 



3. C. fiex'ilis, 15. 1070. (Smooth C.) Smooth, transparent, without 



prickles. Whorled branches cylindrical, blunt, with a minute 

 point, no internal partitions ; some cloven. Bracteas none. 



Ditches and ponds. 0.7, 8. Slender, green, floating. Anth.naked, 



A. C. iranslucens, 26. 1855. (Transparent C.) Smooth, transparent, 



without prickles. Whorled branches simple, cylindrical, obtuse, 



with a small point, and transverse internal partitions; fertile ones 



axillary, compound, partly forked. Bracteas none. 



Pools, rare. 0.6,7. Largestspecies. Whorled br. spreading widely. 



5. C. nid'ifica, 24. 1703. (Proliferous C.) smooth, transparent, with- 



out prickles. Whorled branches simple, elongated, without 

 internal partitions ; fertile ones axillary, compound. Bracteas 

 unequal. 

 Salt-water ditches. 0. 7, 8. More slender. Aspect bushy. 



6. C. gracilis, 30. 2140. (Slender C.) Smooth, transparent, shining, 



