11. L . alpinum, L..—E. Bot. t. 234.
H ab. Elevated parts of the Rocky Mountains. Drummond.
** Foliis distichis, stipulis biseriatis semper superioribus.
12. L . Douglasii; repens dichotome ramosum, foliis distichis ovalibus uninerviis nitidis
integerrimis, stipulis conformibus paululum falcatis apiculatis, spicis terminalibus cylin-
draceis, squamis cordato-acuminatis inferne ciliatis, Hook, et Grev. in Bot. Mise. v. 12.
p. 396.—L. ovalifolium. Hook, et Grev. Ic. Ml. t. 177. [non Deso.)
H a b . Near springs in woody places, N. W. America. Douglas.—An extremely distinct and well-marked
species, which I have never received from any collector except Mr Douglas.
Ord. III. MARSILEACEÆ. B r.
1. ISOETES. L.
1. I. lacustrisi L .—E. Bot.—Ph. Am. 2. p. 671.
H ab. Saskatchawan. Drummond.
2. MARSILEA. L.
1. M. vestita; foliolis cuneatis subobliquis petiolisque appresso-hirsutis, involucris
ovalibus hirsutis axillaribus pedunculo subseque longis. Hook, et Grev. Ic. Fil. t. 159.
H a b . Common on Menzies’ Island and sandy banks o f the Columbia, near the Grand Rapids^ Douglas.
Dr Scouler.—The same species is found at Talisco, Mexico, by the Naturalists of Capt. Beechey’s Voyage. •
Ord. IV. SALVINIACEJE. Bartl.
1. SALVINIA. L.
1. S. natans, L .—Schkuhr, Fil. t. 173. Ph. Am. 2. p. 672.
H a b . Floating on stagnant waters, Canada, Pursh.
2. AZOLLA. Lam.
1. A. Caroliniana, Willd. Sp. PI. p. 451. Ph. Am. 2. p. 672.—A. microphylla, Kaulf.
—Hook, et Am. Bot. of Beech. Voy. p. 162.
H ab . Canada, on the still waters of Lake Ontario. Pursh.—I have not seen British North American
specimens of this singular aquatic. But I do hot think the Californian A . microphylla of Kaulfuss differs
from this, nor this probably from the original A . Magellanica.
Ord. V. EQUISETACEiE. Rich.
1. EQUISETUM. L.
1. E. fluviatile, L .—E. Bot. t. 2022. Hook, et Am. in Bot. of Beech. Voy. p. 404.
H a b . N. W. America. Columbia River. D r Scouler; who observes that the young shoots are eaten in the
Spring as asparagus.—This species extends south into California; and Or Beck gives it as an inhabitant of
Buffalo, N. York, and of the shores of Lake Ontario.
2. E . sylvaticum, L .—E. Bot. t. 1874. Ph. Am. 2. p. 651.
H a b . Canada. Cleghom, Lady Dalhousie; to Fort Franklin on the Mackenzie River. D r Richardson.
Drummond. Newfoundland. Miss Brenton. Mr Cormack. New Brunswick. Mr Kendal.
3. E . umbrosum; caulibus sterilibus pluristriatis superne scabris verticillatim ramosis,
ramis strictiusculis summis subcorymbosis, fertilibus simplicibus demum elongatis verticillatim
ramosis u t in sterilibus.—Meyer in Willd. Sp. PI. 5. p. 3.
H a b . Saskatchawan to the Rocky Mountains. Drummond. Canada. Mrs Perceval.—The young
fertile specimens of this plant from the Rocky Mountains, are marked “ E. Drummondii, Hook.” (Brit. FI.
ed. 4. p. 393, et E. Bot. Suppl. t. 2777): and indeed at first sight I could perceive no difference: but on
examining these specimens carefully, I found on several of them incipient branches, budding out from the base
of the sheaths. There cannot be a doubt, therefore, but these belong to the same species as the specimens
from Carlton House Fort, which Dr Richardson has correctly named “ E . umbrosum," Meyer and Willd.,
and which exhibit fertile and sterile branches from the same creeping root, both throwing out the horizontal
branches. There are likewise fully developed sterile stems in the collection. Now these last, and the simple
(unbranched) fertile plants, are so like our British E. Drummondii, that if we only suppose our fertile plants
of the latter not sufficiently advanced to throw out the branches (and there are comparatively few specimens
which have yet come under my observation), we shall see that the two so-called species are identical, and the
name of Drummondii must give place to umbrosum. Willdenow notices its affinity to E . sylvaticum —
that is, in the peculiarity of the fertile stems throwing off the spike and then branching and becoming similar
to the sterile ones : for the two species are totally distinct.
4. E . arvense, L .—E . Bot. t. 2020. Ph. Am. 2. p. 651.
H a b . Lake Huron, Dr Todd; to the Rocky Mountains and the Saskatchawan. Dr Richardson.
Drummond.
5. E . limosum, L .—E . Bot. t. 929. Beck, FI. p. 446.—E . uliginosum, Willd. ? Ph. Am.
2. p. 651.— (3. Candelabrum; ramorum verticillis numerosis superioribus plurimis spici-
geris.
H a b . Watery places of the Saskatchawan; and P, growing in water about Winipeg. Dr Richardson.
Drummond,—The var. p. has a very curious appearance: it bears copious whorls about 2 inches long, 16-
20 branches in a whorl, and 7 or 8 of these upper whorls bearing spikes, which are much smaller and much
less advanced than the terminal one of the stem.
6. E. palustre, L .—E. Bot. t. 2021.