Wednesday, October 26, 2016

[Botany • 2016] Globba magnibracteata • A New Globba (Zingiberaceae) with Large White Floral Bracts from Peninsular Malaysia

Globba magnibracteata 

Globba magnibracteata Y.Y.Sam, sp. nov. is described and illustrated. Colour plates, a preliminary conservation assessment and a discussion of its closely related taxa are provided.

Keywords: Endemic, ginger, Globbeae, taxonomy, Terengganu, Zingiberaceae

Diagnosis: Globba magnibracteata is similar to G. albobracteata N.E.Br. where both are placed in the subgenus Globba section Sempervirens. They have the same vegetative morphologies and inflorescence structure but differ in having wide spreading or strongly deflexed white sterile bracts versus the green appressed sterile bracts of G. albobracteata. The elliptic fertile bracts of G. magnibracteata are smaller (1.1–1.2 cm long) compared to the obovate bracts of G. albobracteata which are about 3 cm long. The cincinnus stalk of G. magnibracteata is also shorter (less than 1 cm) than that of G. albobracteata (2–4 cm). Globba magnibracteata has bulbils with many roots and one bamboo-like shoot distinct from the one-root-one-shoot bulbils in G. albobracteata.

Etymology: The epithet is derived from Latin and refers to the large (magnusfloral bract (bractea).

Distribution and ecology: Globba magnibracteata is only known from Jengai Forest Reserve, Peninsular Malaysia. The plants were found scattered on the shady and moist forest floor with a thick humus layer in the lowland dipterocarp forest, a tropical evergreen rainforest.

Figure 1. Globba magnibracteata Y.Y.Sam 
Habit Ligule Inflorescence Sterile floral bracts Flower Bulbils.
(Photographs A–F by Y.Y. Sam).  DOI:  10.3897/phytokeys.73.9737

Figure 2. Globba magnibracteata Y.Y.Sam 
A Habit B Inflorescence C Sterile bract D Bracteole E Flower F Ovary and calyx G Dorsal corolla lobe in front and side view H Lateral corolla lobe in ventral and side view I Lateral staminodes in ventral and side view J Labellum K Anther appendages L Stigma.
Drawn by M.N. Aidil from Sam & Aidil FRI 68959 (KEP).   DOI:  10.3897/phytokeys.73.9737

Flowers of Globba corneriGnawawii and Gmagnibracteata G. albobracteata Gcernua G. corneri Gnawawii.
(Photographs I and K by Y.Y. Sam, H by A. Takano, J by Y.M. Chan).  DOI:  10.3897/phytokeys.73.9737  

 Yen Yen Sam and Halijah Ibrahim. 2016. A New Globba with Large White Floral Bracts from Peninsular Malaysia. PhytoKeys. 73: 117-124. DOI:  10.3897/phytokeys.73.9737


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