462 103. cHAKAciLa!. 



spirally sulcata rough brittle -with, scattered blunt tubeydes, 

 branchlets incurved, bracts unilateral ovate-oblong mucronate- 

 acute, nucule shorter than the bract on each side of it longer 

 than the three in front.^C. latifoUa Willd. Hook. Icon. 532. 

 — Opaque, whitish green. St. with minute, distant, rather 

 whorled, short, blunt tubercles on the prominent primary tubes. 

 — Belvidere Lake, Westmeath ; and Shannon below Portumna. 

 Ireland. A. VII. ? I. 



**** Stem coated with 3 times as many tubes as there are 

 branchlets in each tvhorl, tioo secondary between each j^uir of 

 primary tubes, on which latter alone the spines or tvbercles 

 are placed. 



14. C. as'pera (W.) ; dioecious, st. finely striate smooth.flexible 

 with setaceous patent spines, branchlets short, bracts whorled 

 slender (2 inner longer), nucules narrowly oblong shorter than 

 the bracts. — B. B. S. 27S8. — Not opaque, pale green. St. densely 

 crowded ; spines scattered, often very short, or irregularly 

 whorled. Branchlets 6 — 9 in a whorl, of 7 joints, 4 — 5 bracts 

 at each joining. Nucules solitary, strife 12 or 13, crown pro- 

 minent. — Stagnant water. A, VIII. E. I, 



15. Cfrag'ilis (Desv.) ; moncEcious, st. slender finely striate 

 smooth not spinous, last 1 — Z joints of branchlets without e.rternal 

 tubes, bracts on the inner side of the branchlets about as long 

 as or longer than the oblong nucules. — Atl. Fl. Par. 38 C. V. 

 iredtvigiiAg.KB.S.2762. C.pulchellaW&Wr.E.S.S.^S^'L. C. 

 vulgaris L. in part. — Slender, yreen and remaining so throughout 

 the winter, not incrusted; external tubes nearly straight. Nucule 

 with 13 or 14 striae and a long crown, with the globule. Bracts 

 usually shorter than the nucules, one equalling them ; or all 

 longer.— Stagnant water. A. YI.— VIII. E. S. 1. 



"Quanquam multas observaverim plantas et sedulo quidem, 

 tamen non confido me semper veritatem invenisse." — Link. 



