Friday, June 8, 2018

[Botany • 2018] Erythrina calcicola (Fabaceae) • A New Species from Phu Khiao-Nam Nao Forest Complex, northeastern Thailand

Erythrina calcicola Tetsana & Poopath 

DOI  10.20531/tfb.2018.46.1.09 

In the context of an ongoing survey of the limestone ecosystem in Phu Khiao-Nam Nao Forest Complex in Thailand, we describe and illustrate a new species, Erythrina calcicola Tetsana & Poopath. Morphologically, it is particularly similar to E. stricta Roxb. which is distributed in mainland Southeast Asia, but differs in the shape and size of the leaflets, size of the flowers and fruits, and shape of the calyx and the standard blade. Currently, E. calcicola is only known from Tham Pha Sawan temple, Loei province, northeastern Thailand.

 KEYWORDS: Phaseoleae, Erythrina, limestone, northeastern Thailand, conservation status

Figure 2. Erythrina calcicola Tetsana & Poopath in its natural habitat at Tham Pha Sawan temple, northeastern Thailand.
A. habitat; B. bark; C. thorny branches; D. leaf arrangement; E–G. inflorescences and flowers in various views; H. pods; I. immature seed.
Photos by N. Tetsana, 23 March 2017. 

Erythrina calcicola Tetsana & Poopath, sp. nov.

Similar to E. stricta Roxb., but distinguished by the shape of the leaflets, flowers and fruits; leaflets tri-lobed, rarely unlobed (unlobed in E. stricta), calyx cup-shaped or campanulate (spathaceous in E. stricta), standard ovate (elliptic-lanceolate in E. stricta) and fruits cylindric-oblong and constricted between the seeds (strap-like and not constricted between the seeds in E. stricta).
Type: Thailand, Loei, Pha Khao district, Tham Pha Sawan temple, 500 m, 23 Mar. 2017, Tetsana, Hemrat, Suwannachart & Kiewbang 1274 (holotype: BKF!; isotypes BKF!, SING!). Figs. 1–2.

Figure 1. Erythrina calcicola Tetsana & Poopath: A. habit; B. inflorescence; C. flower; D. calyx and dissected calyx; E. standard; F. wings; G. keels; H. diadelphous stamens; I. pistil; J. pod. All from Tetsana et al. 1274. Drawn by O. Kerdkaew.

Etymology.— The specific epithet, calcicola (limestone), refers to the habitat.
Vernacular.— Thong lang hin pun (ทองหลางหินปูน).

Naiyana Tetsana and Manop Poopath. 2018. Erythrina calcicola sp. nov. (Fabaceae) from Thailand. THAI FOREST BULL., BOT. 46(1): 62–66. DOI  10.20531/tfb.2018.46.1.09