Trithuria

Scientific name

Trithuria Hook. f.

Common names

hydatella

Family

Hydatellaceae

Similar genera

Centrolepis, Eleocharis, Isolepis, Littorella

Native distribution

India, Australia, and New Zealand

Species cultivated

Trithuria sp.

Adventive distribution

information not available

Weed status

information not available

Habit

seasonally submergedsubmerged:
(adj) (syn. submersed) under water; submerged below the water surface
, small, sedge-like herb

Brief description

Typically a tufted annual or a creeping perennialperennial:
(adj) (of a plant) having a life cycle of more than two years
. Rhizomerhizome:
(n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns
short, roots numerous, unbranched; stem very short, small, often red. Leaves basalbasal:
(adj) at or pertaining to the base, or point of attachment
, alternatealternate:
(adj) (of leaves) bearing one leaf per node; placed singly on the stem at different heights
to spiral, numerous, erect, glabrousglabrous:
(adj) without hairs or scales
; usually lacking sheaths or ligules; leaf bladeblade:
(n) (syn. lamina) the flat, expanded part of a leaf, frond, or petal (excluding, e.g., the petiole)
linear to filiformfiliform:
(adj) thread-like; long and thin
, basalbasal:
(adj) at or pertaining to the base, or point of attachment
portion hyalinehyaline:
(adj) thin and translucent or transparent
, often buried within sediment, exposed portion dark green to red-brown; apexapex:
(n) the point farthest from the point of attachment; the tip (often pointed)
round to acuteacute:
(adj) tapering to a sharp, pointed apex with more or less straight sides; broader than acuminate; forming an angle of less than 90 degrees
; base straight; marginmargin:
(n) edge; rim
entireentire:
(adj) having a continuous margin that is not toothed or lobed
; venationvenation:
(n) the arrangement of veins in a leaf
midribmidrib:
(n) the main or central vein, line or rib in a leaf or perianth segment
only or lacking. Inflorescenceinflorescence:
(n) the arrangement of flowers on the floral axis
a terminalterminal:
(adj) at the apex
, sessilesessile:
(adj) attached directly, without a stalk
or scapose headhead:
(n) inflorescence consisting of small closely packed stalkless flowers or florets arising at the same level on a flattened axis; of several types, including: discoid (composed entirely of disk flowers) and radiate (composed of central disk flowers and marginal ray flowers)
, bright red apically; involucral bracts lanceolatelanceolate:
(adj) lance-shaped; widest point below the middle, tapering to the apex
to ovateovate:
(adj) egg-shaped in outline; generally with the broad end at or near the base
, in a false whorlwhorl:
(n) three or more similar organs arranged in a circle at the same point around an axis
. Flowers small, unisexualunisexual:
(adj) (of a flower) with either stamens (male) or pistils (female) but not both; consisting of only male or female flowers
; with or without floral bracts; perianthperianth:
(n) collective term for the calyx and corolla of a flower; also used for floral whorl(s) in which the calyx and corolla cannot be resolved; any of the leaves or bracts surrounding the sex organs of bryophytes
absent; male flower a solitary stamenstamen:
(n) the male reproductive organ in a flower, consisting of a pollen-bearing anther and a filament
; female flower a solitary ovaryovary:
(n) a hollow organ at the base of the carpel of a flower in which ovules are produced
, shortly stipitatestipitate:
(adj) borne on a stipe or stalk
, with stigmatic hairs.

Natural habitat

seasonally wet sites, occasionally submergedsubmerged:
(adj) (syn. submersed) under water; submerged below the water surface
; swamps, stream margins, temporary pools, shallow freshwater lakes

Additional comments

A genus of 12 accepted species; 8 endemicendemic:
(adj) restricted to a certain geographical location
to mainland Australia, one each to Tasmania, New Zealand and India; one species (T. submersa) occurs in both Tasmania and mainland Australia.