acutis. DC.—Linn, in “ Act. Ups. 1741. p. 81.” Mich. Am. v. 1. p. 76. Pursh, FI. Am.
v. l .p. 92. De Cand. Prodr. v. 3. p. 67. Elliott, Carol, v. 1. p . 81. Bigel. Fl. Bost. ed. 2
p. 48.
Hab. Canada. Pursh.
2. MYRIOPHYLLUM. VaiU.
Ih re s monoid aut rarius hermaphroditi. $ . Calyx 4-parfitus. Petala 4 lobis cal. alterna
valde caduca ovata. Stam. 4, 6 aut sæpius 8. $ . Calyx ovario adhærens, limbo 4-
lobo. Petala 0. Carpella 4 subconcreta compressa aut subglobosa nucumentacea indéhiscent“
1 1-sperma. Semina in loculis sobtaria pendula, albumine nullo, embryone teretiusculo
inverso, cotyledonibus obtusis, radicula longa— Herbæ aquation notantes, apicibus ad
anthem emersis. Folia opposita aut vertidllata. Flores parvi ad axillas vertmttati, aut
foliis Jloralibm subabortivis verticillato-spicati, super, masculi, infer, foeminei. PC.
1. M. spicatum; foliis verticillatis pinnatipartitis, lobis capillaceis, spica terminali nudi-
uscula, foliis floralibus flore (8-andro) brevioribus, infimis subserratis plerisque integerrimis.
DC.—Linn. Sp. PI. p. 1409. Engl. Bot. t. 83. Mich. Am. v. 2. p. 190. Pursh. FI. Am. v.
1. p. 274. Mich, in Frankl. Is*. Joum. ed. 2. App. p. 36. Bigel. FI. Bost. ed. 2. p. 346.
De Cand. Prodr. v. 3. p. 68.
Hab. Ia pools aad still waters, Canada. Michaux; as far north as the Bear Lake. Dr. Richardson,
Drummond.
2. M. verticillatum ; foliis verticillatis pinnatipartitis, lobis capillaceis oppositis, spica termi-
nali foliosa, foliis floralibus omnibus, pinnatipartitis flores (8-andros) multo superantibus et
a foliis vix distinctis. DC.—Linn. Sp. PI. p . 1410. Engl. Bot. t. 218. Mich. Amiv. 2. p.
190. Pursh, Fl. Am. v. 1. p. 271. Elliott, Carol, v. 2. p . 588. De Cand. Prodr. v. 3. p. 68.
Hab. Stagnant waters, Canada. Michaux.
3. M. tenellum; caule simplice subâphyllo basi radicante erecto, foliis squamæformibus altérais
integris, summis in axilla floriferis, spica terminali interrupta alterniflora. DC.—Bigel.
FI. Bost. ed. 2. p. 346. De Cand. Prodr. v. 3. p . 69.—M. nudum. Lapylaie, MSS. (DC.)
—Hylas aphyllus. Bigel. MSS. in Herb. Boott, apud. nostr.
Hab. In watery places, Newfoundland. Lapylaie, in De Cand. Prodr.—Of this I have seen no
specimen from the British Possessions of North. America ; but it has been found by M. de Lapylaie in
Newfoundland, and in the Northern United States appears to be not unfrequent. I possess excellent specimens
from Mr. Nuttall, Dr. Torrey, and especially from Dr. Boott, and I purpose to illustrate this interesting
plant and its affinity M. procumbens, Bigel. M. (Hylas pinnatus, ejusd. MSS. in Herb. Boott,) by figures in
the Botanical Miscellany.
T r i b . II. C a l l it r ic h in e æ . Link, DC.
3. CALLITRICHE. Linn.
Flores polygami, hermaphroditi, diöici aut sæpihs monoid. Bracteoe 2 oppositæ petal-
oideæ ad basin floris (petala, auct.) Calyx non conspicuus, verosimiliter ovario basi adhærens
limbo abortivo. Petala 0. $ . Stam. 1. (rarius 2) filamentis filiformibus exsertis,
anthera reniformi 1-loculari sutura transversa déhiscente. ? . Ovarium bisulcum quadri-
loculare, in quolibet loculo uniovulatum. Styli 2 filiformes, glandulosi. Capsula compressa
bisulca, constans carpellis 4 concretis per paria approximatis, indehiscentibus, I-spermis,
lenticulari-compressis. Semina cum carpella concfeta, albumine carnoso, embryone inverso
teretiusculo subincurvo, radicula longa supera, cotyledonibus brevissimis.—Herbæ annuæ
aquaticoe teneroe glabroe. Folia opposita. Flores in axillis solitarii, minimi. DC.
1. C. verna; foliis trinerviis superne aggregatis majoribus, fructibus sessilibus, carpello-
rum dorso obtusiusculo. DC.—Linn. Sp. PI. p. 2. Engl. Bot. t. 722.—ß. intermedia; foliis
inferioribus linearibus obtusis aut emarginatis, superioribus ovalibus. Hoffm.—De Cand.
Prodr. v. 3. p. 70. Torrey, Fl. o f Un. St. v. 1. p. 3.—C. verna. Mich. Am. v. 1. p. 2.—C.
aquatica. Bigel. Fl. Bost. ed. 2. p. 2.—C- heterophylla. Pursh, Fl. Am.v. I. p. 3.
Hab. Lakes and pools, Canada. Michaux. Saskatchawan. Dr. Richardson, Drummond. Bay of
Eschscholtz, (a cæspitose vor.) Chamisso. i
2. C. autumnalis; foliis omnibus uninerviis per caulem sparsis æqualibus truncatis, fructibus
sessilibus, carpellorum dorso alato-membranaceo. DC.—Finn. Sp. PI. p. 2. Mich.
Am. v. 1. p. 2. Torrey, FI. o f Un. St. v. 1. p. 4.—C. linearis. Pursh, Fl. Am. v. 1. p. 3.
—C. aquatica, y. Engl. Bot. t. 722, (fig. dextra.)
Hab. Still pools, Canada; about Hudson’s Bay, and as far north as Bear Lake, làt. 66°. Dr. Richardson,
Drummond. Mouth of the Columbia. Dr. Scouler.
3. C. terrestris; foliis omnibus approximatis brevibus oblongis obtusis subsucculentis,
fructibus sessilibus latis brevibus emarginatis. DC.—“ Rafin. Med. Spec. xi. p. 358.” De
Cand. Prodr. v. 3. p. 71. Torrey, FI. o f Un. St. v. 1. p . 4.—C. brevifolia. Pursh, FI. Am.
v. 1. p . 3.
Hab. Muddy places, near the Saskatchawan. Drummond.—I fear this will prove to be only a variety of
C. vema, growing in places less watery than usual. The specimens, however, entirely agree with those I
have received from Drs. Torrey and Schweinitz, gathered in the United States.
T r i b . III. H i p p u r id e æ . Link.
I HIPPURIS. Linn.
Calycis tubus ovario adnatus; limbus minimus integer. Petala 0. Stamen 1 caJycis
margini insertum. Stylus filiformis antheræ sulco receptus. Nux 1-sperma, calyds limbo
marginato coronata; endopleura tumidacarnosa (ex Rich.)', embryonisradicula cylindracea
cotyledonibus longior.-—Herbæ aquaticoe, caule simplici, foliis verticillatis linearibus acutis,
infimis longioribus, fioribus axillaribus sessilibus minimis, nonnullis soepe abortu foemineis
aut neutris.
1. H. vulgaris; foliis 8-12 linearibus acutis apice sphacelatis. Linn. Sp. PI. p. 3. Engl.
Bot. t. 763. Mich. Am. v. 1. p. I ? Pursh, Fl. Am. v. 1. p. 3? Torrey, FI. o f Un. St. v. I.
p. 2. Rich, in Frankl. ls£ Joum. ed. 2. App. p. 2.—y. foliis inferioribus pluries longioribus
membranaceis apicibus intactis.
H ab. Pools of water and margins of lakes, from Canada as far north as lat. 60°. Dr. Richardson,
Drummond. Newfoundland and Labrador. Dr. Morrison. Cape Hope, in Behring’s Straits. Chamisso.
ß. In deep water, plains of the Saskatchawan. Dr. Richardson, Drummond.—The specimen from New-
VOL. I . 2 E