472 103. CHAKACEiE. 



often 3 or 4 feet long. Sterile branchlets 3—4 inches long. 

 Spines variable in quantity and length. — Ponds and ditches. 

 ■yj^ E. S. I. 



7. C. polyacan'tha (Braun) ; st. stout, primary cortical cells 

 more prominent than secondary, many setaceous fascicled 

 spreading spines, 8 — 10 branchlets of 6 — 8 joints, stipulodes 

 long slender, bracts 6 — 10 exceeding the ovoid nuciiles of 13 or 

 13 spires.—/, of B. xviii. t. 208. Atl. Fl. Par. t. 38. B. f. 3.— 

 Very spinous, much incrusted ; smaller, more spinous, with 

 shorter branchlets but longer internodes than C. hispida.- — 

 Ponds and ditches. VI. E. S. I. 



8. C hal'tica (Fr.) ; st. stout finely striate flexible pri- 

 mary cortical cells more prominent than secondary, spines 

 many slender spreading, branchlets 6 — 9 patent many-jointed, 

 stipulodes slender, bracts whorled long exceeding oblong nucules 

 of 10 — 15 spires and spreading crown. — Pale green, not in- 

 crusted. Moderately spinous. Upper part of branches not 

 coated. Bracts very long. Lowest nodes with calcareous 

 bulbils. — Ponds. Kynance Vale, Cornwall. VIIL E. 



h. Dioecious. 



9. C. tomentdsa (L.) ; st. thickened upwards twisted, primary 

 cortical cells very prominent, spines few short stout scattered, 

 branchlets 5 — 7 rather incurved of 4 — 6 long joints the upper 

 joints not coated but inflated, stipulodes usually short and thick, 

 bracts usually 5 very thick the lateral exceeding the ovoid 

 nucules of 12 — 14 spires the others falling short of them. — Hook. 

 Icon. PI. 532. — Opaque, greenish white when fresh, usually 

 much incrusted. Spines rather whorled, very short, acute. 

 Upper joints of branchlets remarkably inflated and lengthened 

 in our plant. — Belvidere Lake and near Portumna, Ireland. I. 



ttt 'Sf- ^l^ 3 rozvs of cortical cells to each hranchlet. 



10. C. as'pera (W.) ; dioecious, st. slender flexible with slender 

 acute spreading spines, branchlets 6 — 9 rather incurved or straight, 

 stipulodes prominent, bracts whorled nearly equal exceeding the 

 ovoid nucules of 13 spires and spreading crown. — E. B. 8. 2738. 

 —Small, in dense masses. Sometimes with smooth calcareous 

 bulbils on lower nodes. Length and number of spines variable. 

 Joints very long. — Lakes and pools. VII. VIII. E. S. I. 



11. C. eon'nivens (Braun) ; dioecious, st. slender brittle with 

 spines, branchlets usually 8 strongly incurved, stipulodes scarcely 

 visible, bracts much falling short of nucules scarcely apparent 



