404 98. EQUISETACES. 
outline attenuated upwards. Fertile st. short, with few (4—5) 
sheaths, appearing before the sterile ones. Sterile and fertile st. 
always distinct.—Damp meadows. P. IV. 
2. E. umbrosum (Willd.); sterile st. with about 20 strize very 
scabrous with prominent points particularly above, branches sim- 
ple with 3 or 4 simple angles, fertile st. simple with numerous 
crowded deeply toothed sheaths.—N. 63. E. Drummondii Hook., 
E. B. 8. 2777.—Sterile st. 1—1} ft. high, nearly naked below, with 
numerous whorls of slender branches in the upper part having 
3- or 4-toothed sheaths, each tooth blunt with one rib vanishing 
upwards ; general outline remarkably obtuse at the top. Branched 
fertile st. with larger sheaths and whorls of about 6 branches ; 
simple fertile st. short (4—6 in.), with numerous loose and still 
larger yellowish-white sheaths with black prominent ribs upwards 
and 12—20 teeth.— Wet places, rare. P. IV. 
3. E. Telmateia (Ehrh.) ; sterile st. nearly smooth with about 
30 striz and branches, branches rough doubly-angular simple, 
fertile st. simple with numerous crowded large deeply toothed 
sheaths.—N. 67. E. fluviatile Sm., E. B. 2022.—Sterile st. 3—6 
ft. high ; occasionally bearing a small terminal catkin ; furnished 
from top to bottom with whorls of slender branches which have 
4 angles each with a longitudinal furrow, and 4-toothed sheaths 
each tooth with 2 denticulated ribs. Fertile st. stout 1 foot or 
more in height with numerous pale brown sheaths with 30—40 
teeth ; catkin large.—Wet places. P. IV. 
** Sterile and fertile stems similar, simple or branched. 
4. E. sylvaticum (L.); sterile and fertile st. with about 12 
furrows and numerous whorls of slender compound spreading or 
defleced branches, sheaths lax ending in 3 or 4 blunt lobes.— 
E. B. 1874. N. 59,--St. 12—18 in. high. Sheaths of the branches 
with 3 lone acute teeth each having a rib extending to its end. 
Fertile st. occasionally simple. Catkin blunt. General outline 
of ee st. pyramidal, of fertile abrupt.—Wet shady places. 
P. IV. V. 
5. E. limosum (L.); st. smooth with many slight furrows, teeth 
of the sheaths short rigid acute, branches erect simple whorled 
often abortive.— FE. B. 929.—Usually growing in water. St. about 
2 ft. high, very smooth, simple below. Sheaths rather short. 
Catkin blunt.—a. E. limosum (Fr.); teeth of the sheaths not fur- 
rowed, sheaths of the branches green with minute black tips to 
the round-backed ribs, branches often wanting. —[8. E. fluviatilis 
(Fr.); st. more deeply furrowed, teeth of the sheaths short dark 
brown acute, rib furrowed on the back.\—In stagnant water. 
[8. Reported to be anative.] P. VI. VII. 
