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II. CELLULAR PLANTS. 
Substance of the plant wholly of cellular tissue (except- 
ing in the Subclass Ductulosce which has a few ducts). 
No woody fibre. No true flowers with stamens and pistils. 
No distinct embryo or cotyledons. 
Class III. 
ACOTYLEDONES or CRYPTOGAMEiE. 
Subclass I. DUCTULOS.E. 
Plants with a few ducts amongst the cellular tissue, but, ac- 
cording to Arnott, no tracheae. 
Order XCII. EQUISETACE^E. 
Leafless branched plants with a striated fistular stem, articu- 
lations sheathed at the base. Sporules surrounded by elastic 
clavate filaments and inclosed in thecac arising from the peltate 
scales of terminal cones. — Vernation straight. Cuticle abounding 
in silex. Only one genus. 
1. Equisetum Linn. Horse-tail. 
* Fertile stems unbranched, succulent ; barren stems with 
whorled branches. 
1. E. fiuviatile (Huds.) ; sterile st. nearly smooth with about 
30 striae and branches, branches rough doubly angular simple, 
fertile st. simple with numerous crowded large deeply toothed 
sheaths. — E. B. 2022. — Sterile st. 3 — 4 feet high, furnished from 
top to bottom with whorls of slender branches which have 4 
angles each furnished with a longitudinal furrow. Fertile stems 
stout, a foot or more in height, with numerous large pale brown 
sheaths with 30 — 40 teeth. — Mr. Newman has shown (Phyt. i. 
532.) that the E. fiuviatile (Linn.) is a variety of E. limosum, 
but I have thought it better to retain the usual nomenclature in 
order to prevent confusion. — Watery places. P. IV. 
