My specimens are not satisfactorj', having only young flowers, and few floating leaves ; it may prove to be a
variety of P. natans. This character I have adopted from the British Flora, the Tasmanian phant agreeing with it, aud
with European specimens.—Floating leaves like those of P. nataxis, but narrower and more membranous ; submerged
ones numerous, narrow lanceolate, stalked, membranous, entire, toothed, ot crisped. Peduncle short, Ihiekened.
upwards.—Some Tasmanian specimens have rigid, wiry stems, and all the leaves lanceolate, opaque, and coriaceous.
This is possibly P. crispus of Mr. Brown, from Port .Tackson, who has added to the specific name “ non Linn.” in
my copy of his ‘ Proclromus.’ Koch refei-s P. heterophyllus, Schreb., to a vaiicty of gramineus, which this plant
may be.
3. Po tam ogetón gramineus (Linn. Sp. PI. 184) ; foliis omnibus submersis linearibus obtusis
membranaceis trinervibus, venis transversis paucis remotis, pedúnculo brevi spica sæpius vix longiore.— Br.
Prodr. 343; Fhigl. Bot. t. 2253.
H a b . South Esk River (growing ly th P. natans), Gunn.
D is t r ib . Europe, India, aud various other parts of the world, as Australia and New Zealand.
A very different-looking and greener plant than the two fonner.—Stems elongated ; branches long, simple.
Leaves 2-4 inches long, i inch broad, linear, blmit, with three parallel veins connected by a few distant transverse
ones. Peduncles short, as are the spikes.
Gen. I I I . RUPPIA, L.
Flores hermaphroditi v. unisexuales, spicati, pauci. Perianthium 0. Stamina 2-4, interdum dissita;
filameutis brevissimis, squamæformibus ; antheris magnis, extrorsis, polline trihedro. Ovaria 4, sessilia,
demum stipitata, 1-locularia; ovulo 1, pepdulo; stigmate sessili, peltato. Fruchis e carpellis 1 -4 longe sti-
pitatis indehiscentibus, gibbosis; semen pendulum, exalbuminosum, uncinatum, cruribus inæqualibus.
Embryo homotropus, macropodus, cotyledone acuminata.—Herbæ gracillimce, cæspitosæ, aqnam salsam
habitantes; xmiSs filifox-mibus ; foliis lineari-setaceis, filiformibus, basi vaginantibus.
A very avidely-distributed plant, forming matted masses of long, very mvrrow, slender, greenish-brown stems
and foliage, in brackish water.—Stems verj' slender, 6 inches to several feet long. Leaves alteniate, sheathing below,
very long, naiTow, and linear. Floxvers in the axils of the leaves. Spadix mneh lengthened after flowering,
and spirally twisted (as in Vallisneria). Ovaries sessile. Peduncles of the finit much lengthened, often an inch
long- Nuts very small, oblique, compressed, with sharp or blunt styles.—An extremely variable plant in Europe,
of which several species have been made on insufiicient grounds. (Named in honour of ITenry Bax-nard Ruppius,
an early German botanist.)
1, R nppia marítima (Linn. Sp. PI. 184).—A?. N . Zeal. i. 236. {Gunxi, 1359, 1359?.)
H a b . Eresli and brackish water near the sea; abundant in the Derwent, Tamar, etc.— (FI. Oct.)
(y. V.)
D is t r ib . Europe and North Africa, Red Sea, peninsula of India, and Ceylon, Australia, Now Zealand,
Sandwich Islands, east and west coasts of North America, West Indies.
Gen. IV. ZANNICHELLIA, L.
Flores monoici. M a sc . Stamen 1, spatha inclusum, axillare, pedicellatum ; anthera sessilis, late oblouga,
2-4-iocularis; pollen globosura. Fcem. Ovaria sub-4, spatha inclusa, pedicellata, 1-locularia, 1-
sperma; stylo recto ; stigmate dilatato ; ovulo 1, péndulo, orthotropo. Nmcm/æ 4, breve pedicellatæ v. ses-
siles. Semen pendulum, exalbuminosum ; testa tenui; cotyledone elongata, circinatim inflcxa ; radicula
maci'opoda.— Herbæ nataxites, tenella, aqua dulcis.
Very sleniler, Boating kerbs, inkabiting frcsb-watcr. Leixa bnear-elongate, 1-3 inches long, 1 line broad.
Flowen monoscions, axillary, solitary, minute, hidden in the spathaceons axils of the leaves. Mxin. A solitary,
naked stamen, mth short filament, and erect, qnadrate, Im - to fonr-celled anther. Folk«, globose. Femaií.
Four ovaries in a spathe. sessile or pedicelled, svith slender styles and peltate stigmas. Fruit of four- linear-oblong,
coriaeeons, minuto nuts, indehiscent, sometimes crenate at back, on long or short pedicels, furnished tvith long or
short styles. Feed oblong, pendulous; teda, membranous; albumen 0 ; radicle very large; eoiyiedow doubled inwards
on the radicle. (Named in honour of John Jerome Zannichelli, a Venetian apothecary and botanist.)
1. Z a nm c h e llin p a lu s t r i s (Liim. Sp. PI. 1375).—i i . S . Zeal. i. 237. ? Z. Preissii, Lelm. ia Plant.
Preus. ii. 3. (Gunn, 1564.)
H a b . Pools of fresh water, abundant: Hobarton, etc.— (c. v.)
D is t iu b . Australia, New Zealand, Europe, North Africa, as far south as the Canaries, North, Central,
and West Asia, India, east and west coasts of North America, and the West Indies.
Gen. V. POSIDONIA, Konig.
Three hermaphroditi, spadice v. pedúnculo basi spatha foliácea bilabiata ineluso. Perianthium 0.
Stamirut. persistentla, sessilia; antheris 3-4., bilooularibus, loculis discretis; filamentis crasse coriaceis, viri-
dibas, erectis, couico-elongatis, utrinque extus basi loculum pollinitorum gerentibus; poUiue confervoideo.
Ovarium i-looulare; ovulo 1, parietaU, ampbitropo; stigmate sessili, villoso, lobato? Frvetus subbaceatus,
indehisceus. &ia«a longitudinalilcr adnatum, exalbuminosum. ®«iryc macropodus; radicaiu maxima,
infera; eotyleivne inficxa, rima longitudinali inclusa.—Herbie marinee: caule repente, ramoeo, fohorum
exuviii veetih: foliis ad apiece ramorum eongeetis, Imean-dmgatie, gramineie : epciíev pedúnculo cra.,sius-
culo e foliorum centro exserto.
Dull-green plants, nfitli creeping rhizomes, growing in salt-water.— short, shaggy with the fibrous
remains of old leaves, and tufts of gi-een, grassy leaves. The species are most commou in tropical seas. Peduncle
or spadix short, arising from the centre of a leaf, its base enclosed iu a two-valved, leafy spathe. Flowers few,
three to twelve (each surrounded by a secondary spathe?). Pex-iaxith 0. Stamens three or four. Anthex-s placed
at the back (outer face) of a broad, persistent, coriaceous filament, that resembles a segment of a perianth. Ovary
one-celled, with one ovule. Fruit a small, fleshy utriculus, with a sessile, plumose stigma. Seed exalbuminous,
attached on one side by all its length to the walls of the pericarp; radicle very large, bent upwards at the apex ?
plumule lying in a slit of the cotyledon.—I have seen detached fndting spikes of the Tasmanian species, in a veiy
bad state; they were found by Gunn, washed up on the beach, and were supposed by him to belong to Cymodocea,
but they so closely accord with the general characters of the European P. oceánica, that I conclude they belonged
to P. australis. (Name from IlocrciSiuv, the god Neptune.)
1. Po sidon ia au stralis (n. sp .); caule breviusculo, ramis abbreviatis exuviis foliorum longissimis
flexuosis dense vestitis, foliis longissime linearibus obtusis, ligula brevissima truncata, spica 4-6-flora.—
Caulinia oceánica, Br. Prodr. 339, xion DC. {Gunn, 1347.)
H a b . Coast of Tasmania, Brown; near Georgetown, below low-water mark, Gunn.
D is t r ib . South coast of Australia.
Stexxis short; branches densely covered with long, ragged, white fibres, 2-3 inches long, the remains of old
leaves. Leaves 2-3 feet long, \ broad, rounded at the tip, nerveless, shining wheu dry. Ligula veiy short, decurrent,
and forming iuflexed margins to the base of the leaf,—I have not seen the flowers of this plant, of which
Mr. Brown says there are four to six on the spike; he refers it to the P. oceaxiica of the Mediterranean Seas,
which is much smaller, with a stiff white brush at the base of the leaves, instead of long, matted fibres. iMr.
Brown further remarks that the four to six flowers of this may distiuguish it.