Meiogyne konkakinhensis B.H.Quang & Tagane

Quang, Bui Hong, Tagane, Shuichiro, Nagahama, Ai, Fujiwara, Tao, Yoneoka, Katsuhiro, Binh, Tran Duc & Oguri, Emiko, 2024, Meiogyne konkakinhensis (Annonaceae), a new species from the central highlands of Vietnam, Phytotaxa 652 (1), pp. 78-82 : 78-81

Meiogyne konkakinhensis B.H.Quang & Tagane , sp. nov. ( Figs 1 , 2 )

TYPE:— VIETNAM. Gia Lai Province: Ayun Municipality, Mang Yang District , Kon Ka Kinh National Park , 14°13′12.71″N, 108°19′34.57″E, 1193 m elev., 14 Dec 2022, fl. & young fr., Oguri et al. Q362 (holotype HN 000076373; isotypes HN 000076374, KAG184835 , KAG185540 , MAK, TNS01353701 , herbarium of Kon Ka Kinh National Park).

The new species is similar to Meiogyne rubra in its relatively small leaf size and reddish purple petals at maturity, but it is easily distinguished by yellowish brown hairy midrib on the adaxial surface of lamina (glabrous in M. rubra ), smaller petals (outer petals 8.0–18.0 × 5.0–8.0 mm, inner petals 7.0–16.0 × 3.1–7.0 mm vs. 30.0–33.0 × 7.5–10.0 mm and 26.5–30.5 × 7.0–8.0 mm), and fewer and smaller stamens (76–80, 1.0– 1.4 mm long vs. ca. 118, 1.5–2.2 mm long), fewer carpels (7–9 vs. 10–11) and more ovules per ovary (7–8 vs. 4).

Trees to 5 m tall with brown bark. Young twigs densely covered with short brown fulvous hairs, old twigs greyish brown, glabrous. Leaves alternate, petiolate; leaf blades oblong-elliptic to ovate-oblong, 2.9–8.2 × 0.9–3.5 cm, adaxial surface dark pale green, glossy, glabrous except midvein, abaxial surface pale green, sparsely covered with long appressed white hairs, apex acuminate, acumen up to cm long 0.6 cm long, margin entire, base acute to cuneate, midrib sunken, covered adaxially with short yellowish brown hairs, prominent, covered abaxially with appressed long white hairs, secondary veins 9–12 on each side, more or less parallel but curving gradually towards leaf margin, prominent on both surfaces, tertiary veins reticulate; petioles 0.2–0.6 cm long, dark brown to black when dry, covered with appressed long white hairs. Inflorescences in axils of leaves or rarely on old branches below leaves, 1-flowered; pedicels 4–6 mm long, densely fulvous hirsute, with 2–3 bracts near base; bracts broadly ovate 1–2 mm long, glabrous adaxially, densely covered with yellowish brown hairs abaxially, apex obtuse to rounded. Sepals 3, broadly ovate-triangular, 2.5–3.5 × 4.0– 4.5 mm, olive-green in vivo, yellowish brown in sicco, sparsely covered adaxially with appressed white hairs, densely covered abaxially with appressed yellowish brown hairs, margin ciliate, apex acute. Petals green, becoming dark reddish purple with age in vivo, yellowish brown or blue-grey in sicco; outer petals spreading at anthesis, ovate-oblong, 8.0–18.0 × 5.0–8.0 mm, tomentose with white hairs on both surfaces, mixed abaxially with yellowish brown hairs, apex obtuse to acute, margin ciliate; inner petals erect or spreading at anthesis, ovate-oblong to rhombic-ovate, 7.0–16.0 × 3.1–7.0 mm, the hairs same as on outer petals, apex obtuse to acute, margin ciliate, with a glabrous, corrugated patch on proximal 1/3 of the adaxial surface. Stamens 76–80, wedge-shaped, 1.0– 1.4 mm long, anther connectives truncate, glabrous. Carpels 7–9 per flower, ca. 2.0 mm long; ovary densely yellowish brown, hairy, stigmas subglobose, ca. 1 mm in diam., sparsely setose; ovules 7–8 per ovary. Fruit of 5–6 monocarps; fruiting peduncle ca. 1.0 cm long. Monocarps (immature) cylindrical, 1.1 cm long, 0.6 cm in diam., densely covered with erect yellow hairs, apex and base round. Seeds not seen.

Distribution: — Vietnam (so far known only from the type locality).

Habitat: —Evergreen broad-leaved forest (transition from hill forest to lower montane forest), 1190 m.

Etymology: —Named for the Kon Ka Kinh National Park.

Phenology: —Flowers and young fruits in December.

Vernacular name: — Thiểu nhụy kon ka kinh (Vietnamese).

Conservation status: —Data deficient (DD). Currently, M. konkakinhensis is known only from a single location in the Kon Ka Kinh National Park. In our field excursion, we found one small population with less than 10 mature individuals, which satisfies criteria of D, critical endangered (CR). However, considering a total area of the national park is 417.8 km ² mostly covered with thick, evergreen broad-leaved forests, more populations could exist in the park and surrounding areas.

Notes: — Meiogyne konkakinhensis is characterised by the several characteristics ( Table 1 ). By a combination of these characteristics, M. konkakinhensis is clearly distinguished from the other species of Meiogyne in Vietnam and surrounding countries. Among the species in Vietnam, it is most like M. rubra , but clearly differs in having the diagnostic characteristics mentioned above ( Table 1 ).

Figures

FIGURE 1. Meiogyne konkakinhensis. A. Flowering branch, view from underneath. B. Flowering branch after anthesis. C. Flower, front view. D. Flower after anthesis, side view. E, F. Fruiting branches, with one monocarp. Photos of Oguri et al. Q362 when it was alive, taken by B.H. Quang.

FIGURE 2. Meiogyne konkakinhensis. A. Flowers, front view, at early stage of anthesis (left), late stage of anthesis (right). B. Outer petals, adaxial (right) and abaxial (left) surfaces. C. Inner petals, adaxial (left) and abaxial (right). D. Flower, bottom view. E. Flower with petals removed showing sepals, stamens and stigmas. F. Sepals, abaxial (left) and adaxial (right) sides. G. Stamens, carpels. H. Stamens. I. Carpels. Photos of Oguri et al. Q362 when it was alive, taken by B.H. Quang.