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Restionaceae |
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A predominantly southern family, Restionaceae is most diverse in Australia and South Africa, with a few species in southern South America and in south-east Asia. In Australia the main centre of diversity and richness is in south-western Western Australia, with a secondary centre in the south-eastern mainland. A few species extend to the monsoonal tropics. Members of the family are almost invariably found on poor, sandy, usually seasonally moist sites in heathlands and heathy forests. Characteristic features of the family Restionaceae in Australia include:
Description
Perennial terrestrial herbs, or aquatic herbs rooted in
the substrate with their leaves emergent. Perennating by rhizomes. Vegetative
reproduction by rhizomes. Stem internodes solid or hollow, terete, strongly
flattened or rarely distinctly angular. Internal secretions not obvious.
Plants glabrous, or with simple or dendritic, non-glandular, unicellular,
uniseriate or multiseriate hairs, or peltate scales. Leaves well developed
or much reduced (i.e. to scales, etc.), alternate and spiral, cauline,
all or mostly basal, or both basal and cauline, sessile. Stipule-like
lobes absent. Lamina simple, symmetric, filiform, acicular, subulate or
linear; base attenuate; margins entire, ±flat; venation parallel,
with the midrib inconspicuous, and the tertiary venation not reticulate;
surfaces not punctate; leathery. Leaf ligule absent. Mostly with male
and female flowers occurring on the same plant or different plants, or
rarely with all the flowers bisexual. Inflorescences terminal or axillary,
consisting of spikelets, racemes or apparent panicles. Bracts present.
Bracteoles present or absent. Pollination by wind. Flowers odourless,
sessile or stalked. Floral disc rarely present. Perianth regular or irregular,
of 1 whorl only, or vestigial, or absent, with (0–) 2–3 or 6 free ±sepaloid
segments, imbricate in bud, cream, green, yellow-brown, grey or black,
without contrasting markings; inner perianth parts herbaceous or papery.
Fertile stamens 2–3 (–6), alternating with and free of the perianth segments,
free of the ovary and style, distinct from each other, all ±equal.
Anthers dorsifixed, versatile, opening inwards by longitudinal slits,
2- or 4-celled. Ovary superior and sessile. Carpels 1–3, fused; ovary
with 1–3 locules. Style terminal, single and unbranched or branching from
the base. Ovules 1–locule, sessile; placentation apical or axile.
Fruit a dry dehiscent loculicidal capsule, or an indehiscent nut; the
perianth on the maturing fruit dry and persistent. Disseminule macro-surface
featureless, or rarely with straight hairs or winged; micro-surface ±smooth
or colliculate, spinulose or papillate, white, dull. Seeds 1–3 per fruit.
Aril absent. Cotyledons 1. Embryo round, shapeless or lenticular.
A treatment of the family Restionaceae has not yet been published in the Flora of Australia. It will appear in Volume 40.
Australian genera of Restionaceae (as recognised for the Flora
of Australia) Acion
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 Anarthria scabra (flowers) Photo: D.Jones © D.Jones
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