Dasymaschalon halabalanum Jongsook & Samerpitak & Damthongdee & Chaowasku 2020, sp. nov.
Creators: name: Jongsook, Hathaichanok
name: Samerpitak, Kittipan
name: Damthongdee, Anissara
name: Chaowasku, Tanawat
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Magnoliales
Annonaceae
Dasymaschalon
Dasymaschalon halabalanum

description: Dasymaschalon halabalanum Jongsook & Chaowasku, sp. nov. (Figs. 2A, 3–5)
Type:— THAILAND. Narathiwat Prov.: Cultivated in Her Majesty The Queen’s 60 th Birthday Anniversary Botanical Garden [originally collected as a sapling from Hala-Bala Wildlife Sanctuary, Waeng Distr., Narathiwat Prov.], 24 April 2018, Chaowasku 180 (holotype: CMUB! [Fig. 4], isotypes: BKF!, G!, P!), in flower.
Diagnosis:— Closely related to Dasymaschalon dasymaschalum, differs primarily by having longer pedicels, larger petals with different color, and a higher number of stamens per flower (see Table 1).
Description:— Shrubs 2–2.5 m tall. Young twigs glabrous. Petioles 5–7 mm long, slightly grooved on upper surface, glabrous on both surfaces; leaf blade elliptic to obovate, 15.3–24.2 × 6–9.2 cm, both surfaces glabrous, apex caudate-acuminate, sometimes less acuminate and more acute, base cordate; midrib raised and glabrous on lower surface, sunken and glabrous on upper surface; secondary veins 10–13 per side, angle with midrib 50°–60° (at middle part of leaf blade). Inflorescences of 1-flowered, axillary (but sometimes appearing as terminal-like); pedicels 5–10.3 cm long, almost glabrous, with ca. 2 bracts at base. Sepals free, broadly triangular, 3.1–3.2 × 4.5–5 mm, outside and margin puberulous with appressed hairs, inside glabrous. Petals free, ± elliptic, 6.3–9.9 × 3.7–6 cm, glabrous on both sides and margin, apex acute. Torus depressed-hemispherical, ca. 2 × 4 mm, apex villous with erect hairs. Stamens 152–175 per flower, ca. 3.1 × 1.1 mm, connective apex acute-obtuse, with an arrow-head appearance, covering thecae. Carpels 16–25 per flower, ca. 3.2 × 1.1 mm; stigmas ± elongated club-shaped, almost glabrous except apex which is puberulous with erect hairs, with a slight lateral groove; ovaries villous, mostly with appressed hairs; ovules 5–8 per ovary, lateral, uniseriate. Fruits consisting of ca. 13 moniliform monocarps borne on a pedicel not less than 6.4 cm long; monocarps 2.3–7 × 0.5–0.6 cm, surface smooth and pilose with appressed hairs, apex apiculate, base contracted into a stipe 7–11 mm long, pilose-villous with appressed hairs. Seeds 2–8 per monocarp, ellipsoid, ca. 8 × 6 mm, smooth and glabrous, raphe slightly raised.
Etymology:— The epithet is derived from “Hala-Bala”, which is the name of a wildlife sanctuary where this species occurs.
Habitat and phenology:— At original location, occurs in evergreen forests. Flowering specimen collected in April; fruiting specimen collected in November.
Additional specimen studied (paratype):— THAILAND. The same place where the type specimens were collected, 4 November 2018, Chaowasku 181 (CMUB), in fruit.
Notes:— Besides Dasymaschalon grandiflorum (see Wang et al.2009), D.halabalanum also possesses considerably large petals (Fig. 5A, B). Both species occurs in the same province and probably the same protected areas; however, they can be readily distinguished by their habit: climbers in D. grandiflorum vs. shrubs in D. halabalanum. The population structure of the new species in Hala-Bala Wildlife Sanctuary and probably adjacent areas (both southern Thailand and northern Peninsular Malaysia) is currently unknown; therefore, the conservation status category “DD: Data Deficient” (IUCN 2012) is herein applied.
description: Published as part of Jongsook, Hathaichanok, Samerpitak, Kittipan, Damthongdee, Anissara & Chaowasku, Tanawat, 2020, The non-monophyly of Dasymaschalon dasymaschalum (Annonaceae) revealed by a plastid DNA phylogeny, with D. halabalanum sp. nov. from Thailand and D. argenteum comb. nov., pp. 265-278 in Phytotaxa 449 (3) on pages 269-270, DOI: 10.11646/phytotaxa.449.3.5, http://zenodo.org/record/13877483