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

Abstract

A. HAY* Typhonium praetermissum and T. taylori (Araceae) are described as species new to science from the Northern Territory, Australia. The first is intermediate in character between Typhonium Schott and Lazarum A. Hay. Consequently, Lazarum is reduced to the synonymy of Typhonium and the new combination Typhonium mirabile is made. The new species are illustrated.

A phylogeny of the Areae (Araceae) implies thatTyphonium, Sauromatum, and the Australian species ofTyphoniumare distinct clades

“…This clade will need to be accorded genus rank to achieve a balanced classification of the tribe, and if Lazarum mirabile A. Hay (Typhonium mirabile (A. Hay) A. Hay) turns out to belong to this clade, Lazarum will become the correct name for this ninth genus of Areae. A revised morphological definition of Lazarum will be necessary, because the characters initially used to define Lazarum (Hay, 1992), viz., the connate spathe base, marcescent spathe (meaning that the withered spathe persists on the plant), annular septum at the spathe constriction, and shoot architecture are shared in only three species, T. mirabile, T. praetermissum, and T. taylori (Hay, 1997). An undescribed species with some of these characters is T. sp.…”

“…The Areae comprise Arum with 29 species (Boyce, 1993(Boyce, , 2006Lobin & al., 2007), Biarum with 21 (Boyce, 2008), Dracunculus with 2 (Mayo & al., 1997), Eminium with 9 (Mayo & al., 1997;Bogner & Boyce, 2008), Helicodiceros with 1 (Mayo & al., 1997), Theriophonum with 5 (Sivadasan & Nicolson, 1982;Mayo & al., 1997), Typhonium s.l. with 72 species (Hay, 1993(Hay, , 1997Sriboonma & al., 1994;Hay & Taylor, 1996;Sookchaloem & Murata, 1997;Hetterscheid & Boyce, 2000;Hetterscheid & Nguyen, 2001;Murata & al., 2002;Wang & al., 2002;Hetterscheid & Galloway, 2006;Dao & al., 2007;Nguyen, 2008: this number includes species here shown to belong in Sauromatum or the Australian clade), and at least 14 as yet undescribed species belonging to various of these genera. For this study, we included 52 species of Typhonium s.l., 18 of Arum, 9 of Biarum, 2 each of Eminium and Theriophonum, both Dracunculus species, and the single species of Helicodiceros.…”

“…The tribe Areae (Araceae) in its current circumscription comprises seven genera (Hay, 1997;Mayo & al., 1997;Hetterscheid & Boyce, 2000) and at least 153 species (including 14 awaiting description). The Areae range from Australia to Europe, with one species in Africa, and a center of diversity in SE Asia, another in the Mediterranean region and the Near East.…”

“…It differs from these genera in its connate spathe tube with two chambers divided by an annular septum. After the discovery of another species from Darwin, T. praetermissum, with spathe tube characters intermediate between Lazarum mirabile and "typical" Typhonium, L. mirabile was transferred to Typhonium (Hay, 1997).…”

Studies on Homalomeneae (Araceae) of Borneo IV:Homalomenaspecimens in the Herbarium Beccarianum-Malesia (FI-B) of the Museo di Storia Naturale—Sezione Botanica “F. Parlatore” dell'Università di Firenze

“…Since the now long out-of-date full revision of Engler (1912) there have been fragmentary floristic accounts by Ridley (1905), Alderwerelt (1922a, b), and Furtado (1935Furtado ( , 1939, an uncritical species listing for Malesia focusing primarily on Sumatera (Hotta, 1985), a revision for New Guinea and the Bismark archipelago (Hay, 1999), and various ad hoc new taxa (Hotta, 1986(Hotta, , 1993, Boyce (1994), Hay & Herscovitch (2002), Sulaiman & Boyce (2005), Boyce & Wong (2008), and Boyce, Wong & Fasihuddin (in press), but no attempt to undertake a full revision of Homalomena. The lack of a reliable taxonomy poses considerable problems for field workers since Homalomena is one of the most speciose and taxonomically intractable aroid genera in the Asian tropics.…”