A new Australian genus of Araceae, with notes on generic limits and biogeography of the Areae

Abstract

HAY, A., 1992. A new Australian genus of Araceae, with notes on generic limits and biogeography of the Areae. A monotypic aroid genus is described from Melville Island, Northern Territory, Australia. The genus is diagnosed in the tribe Areae by its tubular spathe base divided into two chambers by an annular septum. The genus is most closely related to Sauromatum and to some Asiatic, not Australian, species of Typhonium. It is proposed that the geography of the Areae (including Arum, Dracunculus etc.) may now suggest a Gondwanan (rather than Laurasian) and hence Cretaceous (rather than much more recent) origin for the tribe, and its dual arrival in Malesia.

Schismatoglottideae (Araceae) in Malesia I - Schismatoglottis

“…This is in variably marked contrast to the distributions of other fairly large aroid genera, including monoecious Typhonium (Hay, 1992(Hay, , 1993, Alocasia (Hay & Wise, 1991;Hay, 1998) and Homalomena (Hay, 1999), but not dissimilar to Cryptocoryne.…”

Two new species and a new combination in Australian Typhonium (Araceae Tribe Areae)

“…However, it appears from photographs of 71 taylori taken in the Darwin Botanic Garden that the spathe limb is purplish brown adaxially and greyish, speckled purple-brown abaxially and that the appendix is greenish yellow except for a white basal portion. In 71 mirabile, notes accompanying the holotype recorded that the same parts were 'mottled grey green' and 'smokey grey, greenish towards the base' respectively (Hay, 1992). In 71 mirabile the inflorescence develops before the leaves while in 71 taylori the inflorescence is accompanied by one leaf, with further leaves apparently developing later (vegetative material originally collected from the wild had about four leaves per plant).…”

“…Araceae tribe Areae, widely distributed in the eastern hemisphere, was considered to be represented in Australia by two closely allied genera, monotypic Lazarum A. Hay and polytypic Typhonium Schott (Hay, 1992(Hay, , 1993. Hay & Taylor (1996) reported that recent collecting in the vicinity of Darwin, Northern Territory had resulted in the discovery of several putatively new taxa in Araceae tribe Areae, of which two or three were known only sterile or in fruit and so could not be ascribed with certainty to one or other of these genera.…”

“…In it, the basis for distinction of Lazarum from Typhonium breaks down. Hay (1992) distinguished Lazarum from Typhonium by their differing spathe bases. In Lazarum the basal portion of the spathe is tubular and divided by an annular septum into two chambers.…”

A new species of Typhonium Schott (Araceae - Areae) from the Northern Territory, with notes on the conservation status of two Areae endemic to the Tiwi Islands

“…The closely allied A ustralian endem ic genus Lazarum A. Hay, w ith one species, was erected by Hay (1992). Generic delim itation and distribution of the tribe Areae, to which these genera belong, have been discussed by H ay (1992,1993).…”