Miliusa glandulifera Fischer (1926: 453)

Damthongdee, Anissara, Sinbumroong, Aroon, Rueangruea, Sukid, Kaitongsuk, Saksan, Ue-Aree, Phasit, Jongsook, Hathaichanok & Chaowasku, Tanawat, 2022, Miliusa microphylla (Annonaceae), a new species from Thailand as evidenced by morphology and plastid phylogeny, with M. glandulifera, a new record for Thailand, Phytotaxa 532 (3), pp. 259-274 : 267-269

Miliusa glandulifera Fischer (1926: 453) ( Figs. 2C, 2D , 5 , 6 ).

Lectotype (designated here):— MYANMAR [BURMA], South Tenasserim , Mai Nam Wat , Theinkun Chaung, 13 Feb. 1926, Parkinson 1902 ( K! [ K001089907 ], isolectotype: K! [ K001089908 ]).

Description:— Shrub-like treelets 1–1.5 m tall; young twigs tomentose with erect and appressed hairs. Petiole 0.5–1 mm long, glabrous; leaf blade elliptic, sometimes slightly obovate, 7.4–14.6 × 3.8–5.6 cm, glabrous on both sides, base obtuse, slightly unequal, apex ± caudate-acuminate to bluntly acute; midrib raised and glabrous on lower surface, becoming flatter towards apex, slightly raised and glabrous on upper surface, becoming flat towards apex; secondary veins 9–15 per side, rather indistinct, angle with midrib 40°–65° (at middle part of leaf blade). Inflorescences 2- to 3- flowered, axillary, sometimes two inflorescences present in the same axil; flowers pale to yellowish green with washing powder smell in vivo, buds in middle between depressed ovoid and depressed triangular pyramid; peduncle 1–2.5 mm long, glabrous, bracts observed, (broadly) triangular; rachis short when present, glabrous; pedicel (18–) 22–27 mm long, glabrous, bearing 1 broadly triangular bract at midpoint of pedicel. Sepals connate at base, broadly ovate, 1–1.5 × 1.3–2 mm, glabrous on both sides, margin tomentose with erect and appressed hairs. Outer petals ovate, 2.5–2.8 × 1.5–2 mm, glabrous on both sides, margin tomentose with erect and appressed hairs; inner petals broadly ovate, 6.5–7.5 × 5.5–8 mm, glabrous on both sides, margin tomentose with erect and appressed hairs, slightly recurved at anthesis, apex of inner petals broadly acute, glandular structures present inside near base, in middle between crescentshaped and semicircular. Torus ± conical. Stamens 31–33 per flower, 0.8–1 mm long, connective prolongation roundedobtuse. Carpels 6–18 per flower, 0.8–1 mm long; stigmas subglobose; ovaries glabrous; ovule 1 per ovary, basal. Fruit consisting of up to 11 monocarps, black in vivo, borne on a peduncle to 2.5 mm long and a pedicel to 27 mm long; seed-bearing portion of monocarps ± subglobose, 9–10 × 8.5–8.8 mm, smooth, glabrous, not apiculate, stipe 1.5–2.5 mm long, glabrous. Seed 1 per monocarp, subglobose-ellipsoid, ca. 8.5 × 6.5 mm.

Habitat:— Occurs in dry evergreen forests or patches of evergreen forests; at an elevation of 90– 210 m.

Phenology:— Flowering material collected in February (type) and April; fruiting material collected in April.

Distribution:— Myanmar (Tanintharyi Region) and southwestern Thailand ( Fig. 5 ).

Conservation status:— EN B2ab(iii) according to IUCN Standards and Petitions Committee (2019). This species is known by three locations ( Fig. 5 ). Although the AOO is only 6 km 2 based on herbarium specimens, the Thai locations are located in protected areas, with one individual found in Kui Buri National Park (above location in Fig. 5 ) and four individuals encountered in Prince of Chumphon Wildlife Sanctuary, North Side, Upper Part (below location in Fig. 5 ). More individuals in these two locations, hence an estimated AOO of more than 10 km 2 but less than 500 km 2, are expected when more areas have been explored. The Burmese location, however, is considerably disturbed by urban and agricultural expansion.

Vernacular name:— Hat Sa Dee Pi Tak (Thai).

Specimens studied:— THAILAND. Prachuap Khiri Khan: Kui Buri National Park, Khlong Kui Nature Trail , 12°4’27.4’’ N, 99°36’33.7’’ E, 23 Apr. 2019, Kaitongsuk et al. 241 ( BKF, CMUB); Prince of Chumphon Wildlife Sanctuary, North Side, Upper Part , 11°11’33.3096” N, 99°19’17.9904” E, 3 Oct. 2020, Sinbumroong 03102020-2 ( CMUB) .

Based on morphology (e.g. axillary inflorescences, bell-shaped flowers, inner petals being tightly appressed from the base to ± the midpoint at anthesis and translucent structures at the inner petal base) and a matK -exon sequence of Miliusa chantaburiana , this species has been concluded as belonging to clade B ( Damthongdee & Chaowasku 2018), which is confirmed in this study. Miliusa eupoda also possesses the above-mentioned morphological traits (but the translucent structures at the inner petal base are indistinct or absent; Chaowasku & Kessler 2013) and its placement in clade B is herein demonstrated. Unfortunately, the phylogenetic affinities of M. chantaburiana , M. eupoda and several other species in the same clade remain obscure, necessitating inclusion of more variable DNA regions.

With Miliusa microphylla and M. glandulifera added to the list, 23 species of Miliusa are currently recognised in the flora of Thailand.

Figures

FIGURE 2. A. Flower of member in clade CM2 (= Miliusa microphylla, sp. nov.), apical view. B. Flower of member in clade CM1 (= Miliusa mollis), apical view. C. Flower of Miliusa glandulifera, apical view. D. Mature monocarps of Miliusa glandulifera. Photographs by A. Damthongdee (C, D) and T. Chaowasku (A, B).

FIGURE 5. Distribution of Miliusa glandulifera (squares), Miliusa microphylla, sp. nov. (triangles) and Miliusa mollis (circles).

FIGURE 6. Specimen of Miliusa glandulifera collected from Kui Buri National Park, Thailand (Kaitongsuk et al. 241 [SN222215], BKF; = Miliusa glandulifera 1 in Fig. 1).