Cyperacee. | FLORA OF TASMANIA. 79 
styles, one cell, and one pendulous, anatropous ovule. Capsule jointed on to the pedicel, trigonous, of three mem- 
branous valves, which are separated by narrow repla; in dehiscence the valves fall away completely, and the repla 
separate, whence the capsule appears to be formed of six pieces, of which three are broadly elliptical, and alternate 
with as many very narrow ones. Seed cylindric-oblong. (Name from rpeıs, three, and Ovpus, a hole or window ; in 
allusion to the dehiscence of the capsule.) 
1. Trithuria submersa (Hook. fil.).—Juncella Tasmanica, Mueller, in Herb. Hook., and in Cata- 
logue of Victoria Plants, sine descript.). (Gunn, 2014.) (Tas. CXXXVIII. A.) 
Has. Bottom of a lagoon near Macquarrie Harbour, Gunn.—(Fl. Nov.) 
Disrris. Victoria: Hopkins River and Mount Emu Creek, Mueller. 
Prate CXXXVIIL 4. Fig. 1, capitulum ; 2, the same, with the involucre spread open; 3, stamen; 4, pollen ; 
5, female flower; 6, stigma; 7, ripe fruit; 8, ditto, with the valves separate; 9, seed; 10, ditto, cut longitudinally, 
showing the embryo :—all magnified. 
Nat. Ord. XV. CYPERACEA. 
One of the most difficult Tasmanian Natural Orders to investigate, and I am not at all confident 
of having rightly determined several of the genera and species, though I have devoted much labour and 
thought to them, and examined most of the Australian Cyperacee at the same time. The genera are 
to a great extent natural, but their limits are extremely vague, and the technical characters necessary to 
limit them are seldom constant; thus, Chetospora differs from Schenus only in the presence of hypogynous 
bristles, which are often excessively minute, or even evanescent, and some plants almost identical in all 
other points are hence generically separated by this artificial character. These two genera again differ 
from Isolepis and Scirpus chiefly in their scales being distichous; but species of both have imbricating 
scales. The shape of the nut, and its articulation with the base of the style, also afford good characters, 
but often very difficult of appreciation ; and the relative number of scales and flowers in a spikelet is also 
apt to vary, as does the number of stamens and styles, or arms of the style, in the same or most nearly 
allied plants. It is hence almost impossible to determine a few isolated species of the Order, except by 
artificial means, and it is better that the student of Tasmanian Cyperacee should not attempt to make out 
the species until the structure of at least half the genera of the Order is understood, when the value of 
their characters (which are not expressed in absolute terms, but in relative) will become apparent. 
I find about 350 Australian Cyperacee in the Hookerian Herbarium, and there are a considerable 
number of tropical species mentioned in Brown's *Prodromus,' which I am unable to identify with any of 
these, so that I assume that there may be fully 400 known Australian ones. Of these a large proportion 
(fully one-third) are almost exclusively tropical, and a considerable number of them identical with Indian 
and Malay Island plants, often of wide tropical distribution. Of the extratropical species the majority 
are natives of the south-western quarter, and comparatively few are common to this and the south- 
eastern quarter. The Tasmanian species are almost without exception also natives of Victoria and New 
- South Wales; a few of them are common to New Zealand, and some to all temperate and many tropical 
latitudes. 
E Gen. I. CYPERUS, Z. 
Spieule distichz, multiflore ; squamis numerosis, carinatis, omnibus conformibus floriferis, v. paucis 
infimis minoribus vacuis. Sete hypogyne 0. Stylus inarticulatus, deciduus.— Culmi simplices, enodes, 
basi foliati v. vaginati; inflorescentia terminali, involucrata; spiculis sepissime versus apices radiorum 
umbelle congestis spicatisve. 
