Monday, June 24, 2019

[Botany • 2019] Monoon longipetalum (Annonaceae) • A New Species from Sumatra, Indonesia


Monoon longipetalum Nurmawati

in Nurmawati, Ariyanti,  Chikmawati & Kessler, 2019. 

Abstract
A new species Monoon longipetalum Nurmawati from Sumatra is described and illustrated. It is notable for its long lanceolate and narrowed petals to ca. 9 × 0.8 cm, velutinous on upper surface more densely to the apex of the inner and outer petals; large fusiform to 7 × 2 cm and bluntly apiculated monocarps. This new species is similar to Monoon anomalum (Becc.) B. Xue & R.M.K. Saunders and Monoon borneense (H. Okada) B. Xue & R.M.K Saunders for having fusiform monocarp and long bluntly apiculate, but differ in having fewer clustered flowers in each inflorescence, lanceolate, longer, and narrower petals. Detailed morphological characters together with illustrations and diagnostic comparisons are presented. A key to the 19 species of Monoon in Sumatra is provided.

Keyword: Annonaceae, Monocarps fusiform, Monoon anomalum, Monoon borneense, West Sumatra


Fig 2. Photograph of the holotype of Monoon longipetalum Nurmawati (Pitra A. 52). Reproduced with the kind permission of the Head of Andalas University Herbarium (ANDA), Sumatra, Indonesia. 

Fig.1. Monoon longipetalum Nurmawati.
A. Twig with leaves. B. Base of leaf and detail of decurrent. C. Flower. D. Petals, stamens and carpels arrangement. E. Flower bud with sepals (e’) and bracteole (e’’). F. Adaxially sepal. G. Abaxially sepal. H. Stamen. I. Carpel. J. Fruit with two monocarps. K. Monocarp with pericarp removed. L. Seed. Drawn from holotype and isotype Pitra A 52 (A–J) (ANDA) and the paratype H. Hasnah & R. Tamin 221 (K–L) (ANDA).


Monoon longipetalum Nurmawati, sp. nov.

Diagnosis: Monoon longipetalum is morphologically similar to M. anomalum (Becc.) B. Xue & R.M.K. Saunders and M. borneense (H. Okada) B. Xue & R.M.K. Saunders, both occurring in Sumatra with fusiform monocarps, wrinkled surface when dried, and long bluntly apiculate. Although the new species shares some characters with M. anomalum and M. borneense, the three species can be easily individually identified with the combination of characters presented in table 1. 
...

Etymology: The specific epithet longipetalum is referring to the long petals.    

Distribution, habitat and ecology: Monoon longipetalum has been recorded from two locations in West Sumatra: Ngalau Pangian, Lintau Buo and Dusun Kalo-kalo, Tabek Panjang Lintau. Both are in Tanah Datar district. This region is located at elevations between 200 and 500 m above sea level. Rainfall in this subdistrict area averages 172.06 mm per year. This species grows on limestone hills or along river banks. 

    


Subekti Nurmawati, Nunik Sri Ariyanti, Tatik Chikmawati and Paul J. A. Kessler. 2019. Monoon longipetalum (Annonaceae), A New Species from Sumatra, Indonesia. Taiwania. 64(3); 235-239. DOI: 10.6165/tai.2019.64.235