Friday, May 26, 2023

[Botany • 2023] Meiogyne arunachalensis (Annonaceae) • A New Species from the Eastern Himalayas of Northeast India

Meiogyne arunachalensis N.V.Page, 

in Page, 2023. 

The genus Meiogyne is distributed throughout South and Southeast Asia and includes approximately 33 described taxa. A new species, Meiogyne arunachalensis, is here described from the state of Arunachal Pradesh, India. This is the third species from India and the first from the Eastern Himalayan and Northeast Indian region. This species shows morphological similarity with Meiogyne maxiflora, a species distributed in Thailand, but it differs in a number of vegetative and reproductive characters. Meiogyne arunachalensis is the largest species of the genus described so far in terms of tree height and girth of the tree trunk. Detailed colour photographs are provided to highlight its morphological distinctness and facilitate identification in the field.

Keywords: Arunachal Pradesh, Eastern Himalayas, India, Meiogyne, new species

Reproductive characters of Meiogyne arunachalensis N.V.Page, sp. nov.
A, Flower at early anthesis; B, flower at late anthesis;
C, pedicel, bracts and sepals; D, stamens and carpels surrounded by corrugated patch on the adaxial surface of inner petals;
E, fruit with ovoid or ellipsoid monocarps; F, longitudinal section of a young monocarp, showing uniseriate arrangement of seeds.
Photographs: Navendu Page.

Meiogyne arunachalensis N.V.Page, sp. nov.

Meiogyne arunachalensis is morphologically similar to M. maxiflora D.M.Johnson & Chalermglin in size, shape and texture of leaves; position of the inflorescence; and shape and texture of monocarps. Meiogyne arunachalensis is a larger tree, reaching up to 30 m in height with girth exceeding 200 cm (vs height up to 20 m and girth up to 125 cm in M. maxiflora), size of the flowers – outer petals up to 6 cm long (vs outer petals up to 3.5 cm long), corrugated patch 1/3 of the inner petal (vs 1/8 of the inner petal), number of carpels 15–18 (vs 4–6), number of seeds 5 in one row (vs 11 in two rows).

Etymology. The specific epithet refers to the state of Arunachal Pradesh, where the species is described from and hitherto geographically restricted to.

N.V. Page. 2023. A New Species of Meiogyne (Annonaceae) from the Eastern Himalayas of Northeast India. Edinburgh Journal of Botany. 80: 1954.