Sunday, February 25, 2024

[Botany • 2024] Typhonium obtusum (Araceae: Areae) • A New Species from Vietnam


Typhonium obtusum Luu, X.B.Nguyen-Le & H.C.Nguyen,

in Luu, Nguyen-Phi, Q. D. Nguyen, H. C. Nguyen, Van et Nguyen-Le, 2024. 
Bán hạ mo tù  ||  DOI: 10.3897/phytokeys.238.112973

Abstract
Typhonium obtusum is described as a new species endemic to Vietnam. It is unique in the genus in having an oblong-elliptic spathe limb with an obtuse apex and yellowish-greenish filiform staminodes with a down-curved acumen. The ecology, distribution and assessment of the conservation status of the new taxon, as well as a key to all known Typhonium species in Vietnam, are provided.

Key words: Araceae, endemic, new species, Typhonium obtusum, Vietnam

Typhonium obtusum
A whole plants B stem C different forms of leaf blade D inflorescence E spathe and spadix F male, sterile and female zones G stamens H thecae, opened I pistils, cross-dissection J fruits.

 Typhonium obtusum Luu, X.B.Nguyen-Le & H.C.Nguyen, sp. nov.
 
Diagnosis: Typhonium obtusum is morphologically similar to T. rhizomatosum and T. cordifolium in having ovate leaf blades with cordate base, oblong and elongate spathe limb as long as the spadix and an elongated fusiform spadix appendix. However, the novel taxon can be distinguished from T. rhizomatosum by its subcylindrical (vs. globose to subglobose) tubers without (vs. with) rhizomatous offsets, stipitate and fusiform (vs. sessile and conical) spadix appendix) and oblong-elliptic (vs. narrowly triangular ovate) spathe limb and from T. cordifolium by its subcylindrical (vs. subglobose) tubers, leaves without (vs. with) adventitious buds, oblong-elliptic (vs. narrowly triangular ovate) spathe limb and stipitate and fusiform (vs. sessile and cylindrical) spadix appendix.

Etymology: The species is named for the obtuse apex of its spathe limb.

Vernacular name: Bán hạ mo tù (Vietnamese); 
Obtuse-spathed typhonium (English, here proposed).


 Hong Truong Luu, Nga Nguyen-Phi, Quoc Dat Nguyen, Hieu Cuong Nguyen, Hong Thien Van and Xuan Bach Nguyen-Le. 2024. A New Species of Typhonium (Araceae) from Vietnam. PhytoKeys. 238: 119-126. DOI: 10.3897/phytokeys.238.112973