Semina erecta v, liorizontalia ; testa membranácea. Embryo exalbuminosus, ortbotropus v. semi-antitro-
pus ; cotyledone crassa, farinacea, infeme excavata, radiculam includens, infra centrum plumulam minimam
iuvolvens, tubo membranaceo globuHs repleto percursa.—Herbæ minima ; frondibus lenliculañbus, aqnis
duleibus natantibus, marginibus proliferis ; radiculis simplicibus, calyptra majuscula terminatis.
A genus of very cmious minute water-plants, found all over the temperate and tropical parts of the globe,
familiar as “ Duckweed,” covering the surface of stagnant fresh-water with a pale hright-grecn stratum.— Fronds
scale-like, proliferous at the margin, furnished with tufts of thread-like, solitaiy, or tufted roots that have thickened
extremities. Flowers very minute, and seldom produced, included iu slits of the frond, enclosed in a membranous
spathe that bursts irregularly. Stamens two, exserted, unequal, with two-lobed anthers.—The flowers,
which are, when present, detected with difficulty, from their excessive minuteness, may best he found by examining
the yellowish patches of the floating stratum. (Name, the old Greek one.)
1. Lemna minor (Linn. Sp. PI. 1376) ; frondibus ovalibus utrinque planis, radieibus solitariis.—
Br. Prodr. 345 ; FI. N . Zeal. i. 239. {Gunn, 1Ü15.)
H a b . Still waters, abundant.— {v.v.)
D is t r ib . Australia, New Zealand, throughout Europe, Asia, North and South Africa, America, and
the Pacific Islands,
Fronds nearly ovate, compressed, 1-2 lines long, rather thick and succulent in texture, veiy slightly convex
below. Roots solitaiy, Utriculus one-seeded.— “ Lesser Duckweed” of England.
2. Lemna tr isu lca (Linn. Sp. PI. 1376); frondibus lanceolatis petiolatis cruciatim cohærentibus,
radieibus solitariis.—Br. Prodr. 345. {Gunn, 1014.)
H a b . Still waters; less frequent than L. xninor, Broion, Gunn, etc.— (r. v.)
D is t r ib . Australia, Europe, and various temperate and tropical countries.
The “ Ivy-leaved Duckweed” of England.—Fronds f inch long, thin, elliptic-lanceolate, with one extremity
prolonged, the other serrate, pellucid at the margin. Roots solitaiy. Seed solitaiy, transverse, with a short funiculus.
N a t . O r d . VII. T Y P H A C EÆ .
The small Order to which Typlia belongs, may, along with Pistiacea, be reduced to a section of
Aroidea. The only genera belonging to it, Fypha and Sparganium, are both Australian, though the former
only has hitherto been found in Tasmania.
Gen. I. TYPHA, L.
Flores amentacei. Amenta cylindrica, mascula et fceminca eundem culmum vestieutia, másenlo supe-
riore. Flores densissime cougesli, papposi :— M asc. Penanthium 3-setosum, staminibus 3 -6, filamentis
filiformibus liberis v. varie monadelphis, antheris basifixis ;—Eoem. Ovarium l-loculare, longe stipitatum, in
stylum elongatum gracilem, apice lateraliter stigmatosum angustatum, stipite setis capillaribus (perianthio)
plumoso; ovulo unico, péndulo, anatropo. Vtriculm evalvis, raouospermus. Semen pendulum; testa
membranáceo, albumine farináceo, embryone axili, radicula hilo próxima, plumula fissura laterali inserta.—
Herbæ ; rhizomate repente, fibras crassas emittente ; foliis ensiformibus, subspongiosis, integenimis ; culmis
inarticulatis, cylindraceis.
This genus contains the common English Reed-mace, or “ Cat’s-tail,” and is found in most parts of the globe
on the margins of fresh-.water ponds, etc., where it is conspicuous for the cylinchical, bright-brown catkins of pappose
flowers. These yield an immense quantity of pollen, which is pressed into the form of cakes, and eaten in
times of scarcity by the natives of Australia, New Zealand, and Scindc in Western India. The leaves are used for
thatching and other purposes. Rhizomes full of starch, often eatable. The species are not weU characterized ; the
Tasmanian one seems to be the same as the English, though larger tlian the common European state of the same
fim t.—Rhizomes stout, creeping, densely matted together. Oulms 2-4 feet iiigh, cylindrical, solid. Leaves linear,
spongy internally, sheathing at the base, quite entire. Catkins two, towards the apex of each cnlm, the upper of
male°flowers removed a httle distance from the lower. Flowexs minute, most densely matted together, so that the
catkins look like velvet püe. Perianth of capillaiy setæ; male of three to six stamens, with slender filaments;
female of a slender one-celled ovary, tci-minating in a taper persistent style. (Name, tlie old Greek one.)
1. Typha an gustifolia (Linn. Sp. PI. 1377); folds dorso convexis, amenta mascula a foemiiiea
distincta.—-Sr. Prodr. 338 ; FI. N. Zeal. i. 238. ? T. vShuttlewortbii, Soxider et Koch in Koch Synops. FI.
Germ. ed. 2. ii. 785 ; Lehman in Plant. Preiss. ii. 3. {Gumi, 412.)
IIab. Common in marshes, banks of rivers, etc.—{v. w.)
D is t iu b . Australia, New Zealand, and in many temperate and some tropical parts of the Old and
New World.
N a t . O r d . VIII. ALISMACEÆ.
A large Order of water-plants, whose limits are much disputed ; and it seems to be immaterial whether
Alismacea, Juncaginea, and Naiadeee are considered separate Orders, or sections of one. A far more perfect
transition of forms exists between the most perfect Alismacea and the most imperfect Naiadea, than
between Aroidea, Pistiaeea, and Typhacea, which are somewhat similarly connected. All are water or
marsh plants, with solitary or free, superior, one-celled, one-seeded, rarely two- or many-seeded, indehiscent
carpels, bearing one or more erect or pendulous, exalbuminous seeds, with straight or curved embryos.
The floral envelopes are in two series iu Alisma, consisting of three green sepals, and as many white
membranous petals; but tbe transition is perfectly gradual from this perfect double perianth to the naked
stamens and ovary of Ruppia and others. The European genera Alisma and Actinocarpus are both Australian,
but not hitherto found in Tasmania.
Gcu. I. TRIGLOCHIN, L.
Flores hermaphroditi. Perianthium 6-pliyllum, foliolis imbricatis ovato-concavis, 3 interioribus inter-
dum altius insertis, v. 0. Stamina 3 -6 ; filamentis brevissimis, antheris extrorsis. Ovarium 3-6-loculare,
loculis ovulo 1 (rarius 2?) erecto; stylis 3 -6 , stigmatibus sessilibus papillosis v. plumosis. Capsula e
carpidiis 3 -6 axi adnatis, alternis interdum sterilibus septiformibas. Semina solitaria, testa conacea; embryone
exalbuminoso orthotropo.—Herbæ paludosa, scapigera ; foliis linearibus; sca.-p\s gracilibus ; floribus
viridibus, spicatis racemosisve, iiiconspicuis.
Minute or tall slender raarsh-bcrbs, with narrow, grass-likc, or subulate leaves and scapes, bearing spikes or
racemes of inconspicuous green flowers, natives of all temperate regions, move numerous and curious in Australia,
where about ten species are known, than in any other country.—Perianth of four to six greenish, generally unequal
(the outer and lower larger), fleshy, concave leaflets, in two series, the upper generally placed at a little distance
above the others. Stamens three to six, with very short filaments, aud broad, estrorse anthers, often as large as
the sepals in which they lie. Ovox-ies three to six, turgid or bnear, combined into a three- to six-celled ovarj', with
as many one- to two ?-ovuled cells, and sessile plumose stigmas. Fruit of three to six carpels, attached to a central
axis, each ovate, cylindrical, or linear, sometimes keeled, grooved, or armed with a projecting spine below. Seed
solitary, erect, exalbuminous, with a coriaceous testa and straight embryo. (Name from rpm, three, and 7X01x15,
a point ; in allusion to the three eaipels.)