1. T r ig lo ch in tr ia a dm m (Mich. Flor. Bor. Am. i. 208) ; foliis graniineis, floribus pedicellatis,
stamiuibus 3 -6 , fructu subgloboso, carpellis 3 dorso carioatis cum 2 -3 septiformibus alteruautibus, stigmatibus
brevibus recurvis.—FI. N . Zeal. i. 236. T. decipieus, Br. Frodr. 3 4 3 ; Endl. in Plant. Preiss.
ii. 53. T. filifolium, Sieb. PI. Exsic. ; Hook. Ic. PI. 579.
Hab. Sall-marshes ; ahmiAimi, Brown, Lawrence, Gunn, etc.— (FI. Nov.-Jan.) (w. v.)
Disïiub. Australia, from Moreton Island southu'ards and Swan River ; New Zealand, Cape of Good
Hope ; South America, from South Brazil on the east coast, and Chili on the west, southwards ; South
United States.
A slender plant, 3 inclies to 2 feet high.—Root swollen aud bulbous. Leaves narrow, linear, sharp-pointed,
as long as or sliorter than the scape, with membranons sheaths. Scape solitary, flowering part 1-5 inches long.
Flowers very numerous, minute, on spreading pedicels that lengthen after flowering. Sepals ovate, acute or blunt,
variable in size and form. Stamexis variable in number, and particularly in size. Fruit broadly-ovate or elliptic,
one line long, of three compressed carjjels, alternating with as many flat abortive ones. Carpels with tliree ridges
at the back, and veiy shaiqi points.—The Tasmanian specimens have sharper sepals than is usual, and the stamens
are more frequently six.
2. T r ig lo ch in centrocarprim (Hook. Ic. PI. t. 7 2 8 ); pusillum, cæspitosum, foliis filiformibus
scapo brevioribus, scapis plurimis, floribus breve pedicellatis, sepalis membrauaceis valde inæqualibus acuminatis
obtusisve, staminibus 3 -5, fructu lineari apice truncato, carpellis 3 fertiiibus 3 sterilibus altcrnan-
tibus linearibus dorso planis tricostatis, costis lateralibus marginalibus basi breviter calcaratis, stigmatibus
parvis recurvis.—Endl. in Plant. Preiss. ii. 54. {Gunn, 761.)
Var. /S; fructibus brevioribus brevissime pedicellatis divarieatis. {Gunn, 899.)
Hab. Saudy, moist places ; abundant, Gunn. Var./3. Georgetown, Gunn.
Distrib. Victoria and Swan River.
An insignificant plant, 1-2 inches high.—Leaves ^-1 inch long, filiform, narrow, blunt. Scapes numerous,
rigiil and wiry when iu fniit, beaiing a spike of five to ten minute flowers. Fruit on very short pedicels, linear,
i inch long, three-angled or six-angled, the alternate faces much smaller, and formed by the alternate steiile carpels.
Carpels very nan-ow, blunt, with a small, recurved, feathery stigma ; back flat, with three ridges ; the two
lateral marginal produced at base each into a short projecting spine.— Swan River specimens are sometimes twice
a slai'ge as these, with much longer pedicels to the fruit, but the majority do not differ from Tasmanian, The
a ar, ß looks a someivhat different plant because of its small, sessile, spreading (not erect) fruit, but I find tlie same
size of fruit on long pedicels iu Swan River specimens, aud both erect and spreading.
3. T r ig lo ch in p ro c em m (Br. Prodr. 343) ; robustum, elatum, radice tuberibus plurimis, foliis
gramineis linearibus obtusis sæpius supra medium natantibus, scapo solitario, spica elongata, floribus breve
pedicellatis, sepalis obtusis, staminibus 6, ovariis 6 fertiiibus, stigmatibus linearis recurvis papillosis, car-
pellis 6 sæpius obliquis tortisve apicibus divarieatis.— Cycuogeton Hiigelii, Endl. in Ann. Vien. Mus.
ii. 210; Plant. Preiss. ii. 5 5 ; Icoxi. t. 7 3 ; Gen. PI. Suppl.p. 1369.
Var. ß . minor, gracilior, foliis anguste linearibus spica abbreviata.
H ab. Fresh and brackish water ; abundant. Var./3. In pools dried in summer.— (FI. Nov.) (?;. d.)
Distrib. Tropical New Holland, Port Jackson, Swan River, and Victoria.
An extremely variable plant, as Mr. Gunn well remarks, from I to 3 leet higli, and robust in proportion.
The var. ß is smaller and more slender, growing in sandy pools dried up in summer.—Roots of many fibres, bearing
numerous oval tubers i - 1 inch long. Leaves 6 inches to 3 feet long, and i - 2 inches broad, compressed below,
flat above, linear, blnnt, the upper part floating on the water. Scapes solitary, very variable in thickness and
length, some as thick as the thumb, others as a crow-quill. Spikes long or short, of many, sessile, crowded flowers,
that separate aud become pedicelled as fruit is matui-ed. Sepals six, broad, rounded. Stamens six. Ovaries six,
witi) recurved, rough stigmas. Carpels six, obliquely linear or ovate, with spreading, curved poiats, straight or
twisted, inch long.—Endlicher separates this from the genus and Natural Order of Triglochin, on account of
the valvate perianth, two ovules, aud embryo with a large cotyledon, in all which cliaracters, and particularly in the
partially floating leaves, it approaches Potamogetón ; but not only is the whole habit and appearance that of Triglochin
(in which Mr. Brown places it), but I find the æstivation partially imbricated (as much as in some Triglochins),
only one ovule in all the specimens I have examined, and the form of the embryo varies with that of the carpels in
the different species of the genus.
Geu. I I . POTAMOGETON, L.
Flores hermaphroditi. Sepala 4, valvata. Stamina 4, antheris extrorsis. Ovaria 4, sessilia, uuilocu-
laria; ovulo 1, ascendente, infra apicem loculi affixo; stigmate sessili, obliquo. Carpella 4, coriácea v. nu-
cumeiitacea. Semen cüTv&tüxa, exalbuminosum ; testa tenui; radicula incrassata, infera.—Herbæ aquatica ;
caulibus repentibus, demersis ; foliis alternis, rarius oppositis, polymorphis ; stipulis ? intra/oliaceis ; spicis
peduncJilatis, axillaribus, basi vaginatis.
Fresh-water herbs, with leaves often of two forms, the lower linear, grass-like, green, and submerged, the
upper brown and floating, and short, axillary, or terminal spikes of inconspicuous green flowers that project above-
water. In shaUow places the lower leaves are often undeveloped ; in deeper the upper floating ones are sometimes
fewer in proportion. The depth of water and its rapidity, if flowing, cause great variation iu their form, number,
and size. The species are numerous, and many are found in all temperate and even tropical parts of the world.
—Flowers few or many, sessile on short or long fleshy peduncles. Perianth of four nearly sessile concave sepals,
valvate in æstivation. Stamens four, sessile, opposite the sepals; anthers two-ceUed. Ovaries four, sessile, one-
celled, with one curved ascending ovule attached to the axis above the middle. Stigma sessile near the apex.
Carpels four, coriaceous or bony. Seed exalbuminous; testa membranous; radicle tliick, pointing downwards.
(Name from irora/xos, a river, and yeirujv, a neighbour)
1. Potamogetón natans (Linn. Sp. Pi. 182) ; foliis natantibus petiolatis ellipticis oblongis oblongo-
rotundatisve basi subcordatis rotundatis subacutisve, submersis linearibus membrauaceis v. nullis, stipulis
liberis, uucibus dorso carinatis.—Br. Prodr. 343 ; FI. N . Zeal. i. 236. {Guxm, 748.)
Var. minor; foliis minoribus elliptico-lauceolatis.
I I a b . Ponds and still rivers, abundant. Brown, etc.— {t>. v.) Var. B- Lake River, Gritidelwald,
Gunn.
D is t r ib . Over most parts of the world, from the Arctic Circle to tbe Cape of Good Hope, South
Chili, New Zealand, and Australia; also found in the Pacific Islands.
A common and very variable plant, often covei-ing the surface of the water with its red-browm foliage.—Leaves
floating, 1-3 inches long, stalked, elliptical or oblong, more or less broad and sharp at both ends, or blunt or cordate
at the base ; submerged leaves none, or linear, green, membranous. Spike 1-2 inches long. Nuts keeled at
the back.—The var. ¡3 resembles the European P. helerophyllm, and has smaUer, sharper leaves, partly owing to
its growing in running water, and partly to the elevation of its habitat (1500 feet). I have not seen its fruit.
2. Potamogetón hete rop hy llus (Sclireb. Spic. FI. Lips. 21 ?) ; foliis natantibus petiolatis oblongis
ellipticis elhptico-lanceolatisve, submersis membranaccis sessilibus V. breve petiolatis lanceolatis utrinque
angustatis integerrimis crispatis deuticulatisve, stipulis nervosis, pedunculis siiperne inerassatis.—A’« / .
Bot. t. 1285.
I I a b . Derwent River, above New Norfolk, Gu7tn.— { v .v )
D is t r ib . Europe, India, and probably many other places.
VOL. II.