The family of plants that includes the kangaroo paws is known as the Haemodoraceae. The family takes its name from the genus Haemodorum which is found in various parts of Australia as well as in New Guinea. The Haemodoraceae is a family of herbaceous plants related to the lilies (Amaryllidaceae). There are about 14 genera in the family comprising over 100 species. The family is mainly concentrated in the southern hemisphere, being found in tropical South America, Central America and the Southeast of North America, as well as southern Africa, Australia and New Guinea.
Botanically the Haemodoraceae is divided into two subfamilies, the Haemodoroideae and the Conostylidoideae, both of which contain Australian species. The Conostylidoideae are best known horticulturally, as this subfamily includes the famed kangaroo paws of the genus Anigozanthos. These are striking and distinctive plants, and, thanks to modern breeding and hybridization, widely grown in cultivation across a range of climates. The table below indicates the Australian members of the family.
Australian Genera in the Haemodoraceae*
|Genus||No.of Species*||Common Name||Distribution|
|Haemodorum||Bloodroots||South-western, northern and eastern Australia, including Tasmania, and New Guinea|
|Anigozanthos||Kangaroo paws/catspaws||Southwest Western Australia|
|Blancoa||Red bugle||Southwest Western Australia|
|Conostylis||Cone flowers||Southwest Western Australia|
|Macropidia||Black kangaroo paw||Southwest Western Australia|
|Phlebocarya||None||Southwest Western Australia|
|Tribonanthes||None||Southwest Western Australia|
|*||Approximate number only; some genera contain unnamed species and other genera are in need of botanical revision..|
In general, the Australian members of the Haemodoraceae are small, strappy-leaved, clumping plants occasionally reaching 1 metre wide and high, but usually much smaller. The leaves arise from an underground stem, known as a rhizome, and flowers occur in terminal clusters on stems arising from the base of the leaves. These flowering stems may be shorter or longer than the leaves, depending on the genus. Flowers have little or no fragrance.
In some cases, the leaves die back to the underground rhizome after flowering and seed production has been completed and then only reappear the next season following rainfall. During very dry seasons, plants may remain dormant (not produce leaves and flowers) for several consecutive years. This can sometimes give the impression that the plants have disappeared from their natural habitat whereas the underground rhizomes may still be viable. Examples of this type of response to environmental conditions can be seen in the tropical Haemodorum coccineum and in kangaroo paw species such as Anigozanthos humilis and A.preissii. However, other kangaroo paw species may persist in leaf more or less indefinitely. The best known example of this is the robust A.flavidus, a very vigorous species whose leaves may reach 1 metre high with flowering stems as high as 3 metres. Other kangaroo paw species which usually remain in leaf permanently are A.rufus, A.pulcherrimus and Macropidia fuliginosa.
The main pollination vectors used by Australian members of the Haemodoraceae are birds, small marsupials and insects. Often the flower structure of particular species gives a guide to the particular pollinators for that species.
For example, a kangaroo paw flower is long, narrow and tubular-shaped with protruding, pollen-bearing structures (anthers) and a protruding pollen-accepting structure (stigma). These seem ideally designed for low-beaked birds which seek out the nectar deep from within the flower and at the same time are either dabbed with pollen from the anthers or deposit pollen from another flower on the stigma. Kangaroo paws are also often pollinated by small nectar-feeding marsupials such as the small honey possum.
On the other hand, the open flowers of Conostylis species seem less likely to require such specialised pollination. Observations have confirmed that these are generally insect pollinated.
In common with other members of the Australian flora native to fire-prone areas, Australian members of the Haemodoraceae have developed two broad strategies in coping with bushfires: