Synonyms: Centrolepidaceae APNI*
Description: Perennial herbs with a rush- or sedge-like habit; tufted or with creeping rhizomes often partly covered by scales; or (subfamily Centrolepidoideae) diminutive tufted annuals. Stems (culms) green, terete to angular or flattened, simple or branched, straight or flexuous, solid or hollow.
Leaves in adult plants reduced to sheaths, often with a small linear or subulate lamina; sheaths closely imbricate or loose, margins overlapping, at least at the base, or (Centrolepidoideae) leaves not reduced to sheaths.
Flowers in spikelets, usually with imbricate rigid glumes, some of the outer ones usually empty; in several genera the spikelet structure not apparent because of clustering of spikelets; spikelets 1–many-flowered, either similar or very different in the 2 sexes, solitary and terminal, or axillary, or arranged in a racemose inflorescence. Male and female inflorescences either similar or very different. Flowers usually actinomorphic, 3- or 2-merous, bisexual or more usually unisexual and plants dioecious, in some species bisexual or monoecious, small, each in the axil of a ± scarious glume; bracts on pedicel 1 or 2 or absent. Perianth in 2 whorls, rarely absent; tepals 3–6, glume-like or scarious, erect. Male: stamens 2 or 3, opposite the inner tepals; filaments free and filiform; anthers 1-locular, dorsifixed, exserted or not-exerted, dehiscing by longitudinal slits; pistillode often present. Female: staminodes 2, 3, or absent; ovary superior, sessile or shortly stipitate, 1–3-locular according to the number of carpels fully developed or (Centrolepidoideae) carpels numerous on an extended axis; styles or style branches1–3; ovule solitary in each loculus, pendulous.
Fruit a loculicidal capsule, 2- or 3-angled or 1-locular, or a small nut.
Distribution and occurrence: World: 40 genera, 585 species, all except 1 species Southern Hemisphere, with main centres of diversity in southern Africa & SW Australia, also in E Australia, New Zealand, New Guinea, Malesia, Chile & Falkland Is. Australia: 24 genera, c. 160 species, all States.
Restionaceae characteristically occur on sandy or peaty soils low in nutrients, often in seasonally wet sites.
Angiosperm Phylogeny Website (Family: Restionaceae, Order: Poales)
Restionaceae characteristically occur on sandy or peaty soils low in nutrients, often in seasonally wet sites. The classification of Australian Restionaceae depends largely on phylogenetic studies (Briggs et al., Taxon 63: 24–46 (2014), also see Restionaceae in online Flora of Australia. The species formerly known in Australia as Restio are not closely allied to the true Restio species of South Africa.
Centrolepis and Aphelia were formerly placed in family Centrolepidaceae but, following analyses of DNA data, this family is now included in Restionaceae as subfamily Centrolepidoideae. The diminutive plants of this subfamily in many ways resemble seedlings of other Restionaceae. The inflorescence of Centrolepidoideae was formerly interpreted as a pseudanthium, including a number of male and female flowers each consisting of a single stamen or carpel, but this has been reinterpreted and is seen as a bisexual flower in a spikelet structure. The carpel number is increased from that in other Restionaceae with the carpels borne separately on an elongated axis.
Text by A. L. Quirico & B. G. Briggs, updates B.G. Briggs, Aug. 2022
| ||Key to the genera|| |
|1||Inflorescence a spike with 6–11 distichous bracts||Aphelia|
|Inflorescence a head enclosed by a pair of bracts||Centrolepis|