Description: Perennials with stems arborescent or subterranean, woody, covered with packed leaf bases.
Leaves crowded in a terminal crown, narrow-linear, tapered, rhombic to cuneate in T.S.; margins with microscopic trichomes, rarely hairy; leaf base broad, sometimes thickened.
Inflorescence cylindrical, spike-like, on a woody scape; flowers in spirally arranged clusters subtended by cluster bracts and surrounded by packing bracts that fill out the spaces between the flowers and form the surface of the spike. Flowers actinomorphic, 3-merous, bisexual and either fertile or aborted. Tepals 6, free, in 2 whorls; outer tepals papery or scarious; inner tepals membranous, apices exserted. Stamens 6, longer than tepals; filaments flattened; anthers dorsifixed, 2-locular, introrse, dehiscing by longitudinal slits. Septal nectaries exude copious nectar. Ovary superior, 3-locular; ovules several per loculus; style simple; stigma entire, sometimes grooved.
Fruit a capsule, obtuse or pointed, the hardened style base ± exserted; seeds 1 or 2 per loculus, ovate, usually semi-matt black, rarely ovoid and shining (in 1 species).
Distribution and occurrence: World: 1 genus, 28 species, endemic Australia. Australia: all States.
Angiosperm Phylogeny Website (Family: Xanthorrhoeaceae, Order: Asparagales)
Note: leaf shape is T.S., and breadth and thickness are taken at the mid-point along the length of the leaf. Scape diameter is measured just below the spike, and spike diameter is measured at the surface of the bracts at the broadest point of the spike.
The surface of the spike is formed of fertile and aborted flowers and packing bracts and cluster bracts. The bracts vary considerably in size and shape (see diagram below), the described shapes are for mature bracts; these bracts should be distinguished from the outer tepals of aborted flowers which are larger and are similar in most species. Cluster bracts vary from prominent to obscure in mature spikes.
Tepals are beaked, and/or with a proboscis, and/or with a central outer ridge, or recurved. A beak is a continuation of the tepal into a terminal appendage that has a small tuft of papillose hairs. A proboscis is a small adaxial surface projection from the beak or apex; it is always hirsute with papillose hairs.
This family is now probably to be included in Asphodelaceae s. lat.
Text by D. J. Bedford (1993); edited KL Wilson (July 2015)
Xanthorrhoea. A–F, shapes of packing bracts; A, obtuse; B, short-acute; C, acute; D, triangular; E, narrow-triangular; F, subulate; G–M, leaf shapes in T.S.; G, transverse-linear; H, concave; I, depressed-cuneate; J, depressed-obtrullate; K, transverse-rhombic; L, narrowly transverse-linear; M, quadrate-rhombic.
|One genus in NSW: Xanthorrhoea|