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Agavaceae


This is a moderate-sized tropical and subtropical family, particularly rich in Central America. Some species of Agavaceae (e.g. Yucca, Agave) are garden escapes, mostly in south-eastern Queensland but with a few species occasionally seen in dry parts of southern Australia. The native genera Cordyline and Pleomele are found in rainforests, swamp forests and wet eucalypt forests, from the Top End of the Northern Territory through coastal Queensland to central-coastal New South Wales.

Characteristic features of the family Agavaceae in Australia include:

  • robust plants often forming large clumps with long, often spiny, linear leaves
  • flowers more or less tubular in large racemes or panicles, white or brightly coloured
  • six perianth parts and 3-carpellate ovary with unbranched style, the ovary developing into a capsule or (often red) berry

Description

Evergreen trees, shrubs, or perennial terrestrial herbs; if herbs then perennating by rhizomes or taproots; sometimes perennating by detached stem parts. Internal secretions not obvious or of coloured sap. Plants glabrous. Leaves alternate and spiral, or in whorls or pseudo-whorls, all or mostly basal if herbs, petiolate, subsessile or sessile. Stipule-like lobes absent. Lamina simple, symmetric, filiform, acicular, subulate, linear, lanceolate, ovate, elliptic, oblanceolate, obovate or oblong; base cuneate, attenuate or rounded; margins entire, crenate, dentate or serrate or spiny; venation parallel, with the midrib conspicuous, and the tertiary venation not reticulate; surfaces not punctate; herbaceous, leathery or succulent. Plants with all the flowers bisexual. Inflorescences terminal, consisting of panicles or monochasial cymes. Bracts present. Pollination by insects, birds or bats. Flowers fragrant or malodorous; stalked. Floral disc absent; nectaries possibly present on the carpels. Perianth regular, of 2 dissimilar or ±similar whorls, each of 3, fused, petaloid segments, the outer whorl alternate with the inner whorl, valvate in bud, tubular, white, cream, yellow, red, grey, brown or black, membranous or succulent; lobes ±entire. Fertile stamens 6, opposite to and free or at least partly fused to perianth segments, distinct from each other, all ±equal. Anthers dorsifixed or basifixed, versatile, opening inwards by longitudinal slits; 2-celled. Ovary superior or inferior. Carpels 1 or 3, fused; ovary with 2 locules. Style terminal, single, branched above or from the base, or absent and the stigma ±sessile on the ovary. Ovules 1–numerous per locule, stalked; placentation axile. Fruit a dehiscent, loculicidal capsule or a fleshy, indehiscent berry; the perianth on the maturing fruit deciduous or dry and persistent. Disseminule micro-surface ±smooth, red, magenta, purple, violet, brown, grey or black, glossy or dull. Seeds 1–numerous per fruit. Aril absent. Cotyledon 1. Embryo straight.
(Note: this description has been generated from the coded data compiled for the key. Any errors in the key data will be reflected in the descriptions.)

A treatment of the family Agavaceae has been published in:
Flora of Australia 46: 71-88.

Australian genera of Agavaceae (as recognised for the Flora of Australia)

* = all species introduced

*Agave
Cordyline
Doryanthes
Dracaena
Furcraea
*Phormium
Pleomele
*Sansevieria
*Yucca


Agave americana (habit)
Photo: M.Fagg © M.Fagg 


Cordyline congesta (flowers)
Photo: M.Fagg © ANBG 


Cordyline rubra (flowers)
Photo: H.Nicholson © H. & N. Nicholson 


Cordyline rubra (fruits)
Photo: M.Fagg © M.Fagg