 |
| Dischidia argentii Arshed, J.R. Callado & Tandang, in Arshed, Callado, Tandang, ... et Rodda, 2021. |
Abstract
We document the taxonomic history of Dischidia ruscifolia Decne ex Becc. After a critical study of the available original material and additional specimens an epitype is designated. We confirm that D. myrtillus is a synonym of Dischidia ruscifolia and the name is typified. Clarification of the identity of D. ruscifolia allowed the identification of a new species that is here published and illustrated as Dischidia argentii Arshed, J.R. Callado & Tandang. The new species differs largely in its floral morphology and particularly in its glabrous corolla throat, absent corolline corona, gynostegium outline, and pollinium shape.
Keyword: Epiphyte, epitype, lectotype, Philippines, typification
 |
| Dischidia ruscifolia Decne ex Becc. A. Habitat, B. Habit, C. Flower top view, D. Flower side view. Photos by N.K. Alfeche. Scale bar: A = 1 cm; B = 5 mm; C = 1 mm; D = 1 mm. |
Dischidia ruscifolia Decne ex Becc. Malesia 2: 272
(1886).
Distribution and Ecology: Endemic to the
Philippines. Its distribution goes from North Luzon up to
Mindanao (Fig. 2). The observed and collected specimens
from Mt. Arayat, Pampanga were seen at 605 masl up to
the peak at 1030 masl. Notes from the examined sheets
concur with Merrill (1923) and Elmer (1938) records
wherein this species can also be found along rivers, peaks
and even at cliffs.
Vernacular name: Kabkab (Visayan), Million hearts (English)
 |
| Dischidia argentii Arshed, J.R. Callado & Tandang, sp. nov. A. Flowering branch, B. Flower, side view, C. Calyx and gynostegium, side view, D. Pollinarium, E. Fruit. Drawn by X.Y. Loh, based on D. Tandang & J.R. Callado s.n. (PNH). Scale bar: A = 1 cm; B = 0.5 mm; C = 0.5 mm; D = 0.05 mm; E = 1 cm. |
 |
| Dischidia argentii Arshed, J.R. Callado & Tandang, sp. nov. A. Habit, B. Flower top view, C. Habit showing the follicles, D. Leaves. Photos by J. R. Callado. Scale bar: A = 1 cm; B = 1 mm; C = 1 cm; D = 1 cm. |
Dischidia argentii Arshed, J.R. Callado & Tandang, sp.
nov.
Diagnosis: A species similar to Dischidia ruscifolia Decne ex Becc. because both species are small epiphytic
sub-shrubs with erect stems becoming pendulous upon
maturity, with densely placed leaves of similar size and
shape (cordate-ovate) They are separated by the corolla
throat surface (glabrous in D. argentii, vs surrounded by
a single layer of stiff hairs in D. ruscifolia), corolline
corona (absent in D. argentii, vs present in D. ruscifolia),
gynostegium base (stipitate in D. argentii, vs subsessile
in D. ruscifolia), and pollinium shape (clavate in D.
argentii, vs oblong in D. ruscifolia).
Etymology: The new species is named after the late Dr.
George Argent (1941–2019), for his contribution to the
flora of the Philippines as he steered numerous biodiversity
studies and taxonomical discoveries in the Philippines.
Distribution and Ecology: Only known from the type
specimen from Mt. Kilang, Ilocos Norte (Fig. 2), growing on a tree trunk or fallen branches in a montane forest at
1300 masl and was collected along the forest trail near the
road traversing Ilocos Norte and Apayao exposing some
of the population to anthropogenic disturbance.
Muhammad Jefte Arshed, John Rey Callado, Danilo Tandang, Akiyo Naiki, Esperanza Maribel Agoo and Michele Rodda. 2021. The Taxonomy of Dischidia ruscifolia (Apocynaceae, Asclepiadoideae) and the Description of A New Species, Dischidia argentii. Taiwania. 66(4); 496-503.
