Wednesday, May 13, 2015

[Botany • 2014] Notes on Singapore native Zingiberales I: Zingiber singapurense, A New Species of Zingiber and notes on the identities of two further Zingiber taxa


Fig. 1. Zingiber singapurense Škorničk.
A. Habit. B. Inflorescence. C. Rooting plantlet arising from the apical part of the leafy shoot. D. Detail of ligule. From type SNG-178.
(Photos: Jana Leong-Škorničková)


ABSTRACT
A new species of Zingiber singapurense Škorničk., is described and illustrated here. It is compared to other species from the Zingiber gracile (Zingiber sect. Zingiber) alliance. A key to this group of species in Peninsular Malaysia and Singapore and a key to all Singapore native and naturalised Zingiber species are provided. The national and international conservation status of the new species and a conservation strategy for it are discussed. Notes on the varietal identity of Zingiber puberulum and the presence of Z. ottensii, previously misidentified as Z. zerumbet, in Singapore are given. 


Keywords: Central Catchment Nature Reserve, conservation, IUCN, Zingiber gracile, Z. griffithii, Z. ottensii, Z. puberulum, Z. singapurense, Z. zerumbet, Zingiberaceae



Ecology and phenology. Zingiber singapurense occurs in primary and mature secondary forest, preferring moist and shady conditions. Flowering in May–June.

Distribution. So far endemic to Singapore.

Etymology. The specific epithet of this small and vulnerable yet resilient species is derived from Singapore’s name in Malay, ‘Singapura’.

Provisional IUCN conservation assessment & conservation strategy. So far only three populations in the Central Catchment Nature Reserve have been discovered with each population only having 10–25 mature individuals and less than 50 mature individuals in total. The Extent of Occurrence (EOO) is 0.06 sq.km. High visitor numbers and proposed development plans could adversely affect the quality of the habitat. Following the IUCN criteria (IUCN, 2012) and the criteria for national conservation assessments as outlined by Davison (2008), Zingiber singapurense should be considered nationally and globally Critically Endangered (B1ab(iii,iv,v); D). 


Key to native and naturalised Zingiber species in Singapore 
1a. Spike ovoid, bracts rusty purple brown at anthesis, peduncle equal or more than double the length of spike (> 15 cm long), labellum and staminodes tinged by light purple to violet, with light yellow blotches ................................... Z. ottensii 
1b. Spike fusiform, bracts pink, orange or red at anthesis, peduncle as long or shorter than spike (< 15 cm), labellum and staminodes uniformly pale yellow .............. 2
 2a. Plant less than 1.5 m tall, bracteole less than 6 mm or absent ............................. 3
2b. Plant over 1.5 m tall, bracteole more than 10 mm ............................ Z. puberulum 
3a. Lamina elliptic, bright green, thin, weakly plicate, beneath with long silky appressed hair, bracteoles absent .......................................................... Z. griffithii 
3b. Lamina narrowly ovate, dark green, slightly leathery, flat (not plicate), glossy, glabrous beneath, bracteoles reduced (2–7 mm long) .................. Z. singapurense


J. Leong-Škorničková, A. Thame and P.T. Chew. 2014. Notes on Singapore native Zingiberales I: A new species of Zingiber and notes on the identities of two further Zingiber taxa. Gardens’ Bulletin Singapore. 66(2): 153–167. 

No comments:

Post a Comment