Agapetes heana Y. H. Tong & J. D. Ya, 2021

Tong, Yi-Hua, Bai, Ying, Feng, Jian-Ming & Ya, Ji-Dong, 2021, Agapetes heana, a new species of A. ser. Longifiles (Ericaceae) from Yunnan, China, PhytoKeys 180, pp. 133-139 : 133

Agapetes heana Y. H. Tong & J. D. Ya sp. nov.

Figures 1 , 2

Type.

China. Yunnan Province: Lüchun Xian, Huanglian Shan National Nature Reserve , elev. 1803 m, 4 March 2021 (fl.), J. H. He 210304 (holotype KUN) .

Diagnosis.

Agapetes heana is similar to A. inopinata Airy Shaw and A. oblonga Craib in the leaf blade shape, the glandular hairy inflorescence and the filaments that are longer than thecae, but can be distinguished from the latter two by its bead-like tubers (vs. spindle-shaped), leaf blade with a wholly serrulate margin (vs. entire, or inconspicuously serrate beyond middle, or sparsely denticulate at apex), subulate (vs. triangular) and much longer (7-8 mm vs. ca. 1 mm and 1.5-2.0 mm, respectively) calyx lobes, much larger (ca. 3.5 cm vs. ca. 0.8 cm and 1.3-1.9 cm, respectively) corollas that are carmine, green at the apex and maroon on angles (vs. red, crimson or carmine), and longer (ca. 3.6 cm vs. ca. 0.7 cm and 1.0-1.5 cm, respectively) stamens that are without spurs on the back (vs. with 2 obvious short spurs) (Table 1 ).

Description.

Evergreen shrub, epiphytic on trees. Tuber globose, 1-3 cm in diam, bead-like. Stems and branches slender, obliquely spreading. Twigs greyish brown, terete, 2-3 mm in diam., densely glandular-setose and pubescent, glabrescent when old. Leaves sub-distichously scattered; petiole 2-3 mm long, pubescent adaxially, glandular-setose and pubescent abaxially; leaf blades thinly leathery or firmly papery, ovate to ovate-lanceolate, 4.5-7.0 × 1.5-2.6 cm, adaxially glabrous except the pubescent midvein, abaxially sparsely glandular-setose, more so on midvein, trichomes deciduous when old, midveins conspicuously raised above, slightly raised below, secondary veins 6-11 pairs, with veinlets conspicuous on both sides, base rounded to slightly cordate, without basal glands, margin slightly revolute when dry, each side with 20-24 serrula, each serrula with a glandular seta at the tip, setae deciduous, apex caudate-acuminate. Inflorescences shortly racemose, 2-3-flowered, 0.3-1.0 cm long, pseudo-terminal, densely glandular-setose and pubescent; bracts unknown; pedicels 9-10 mm long, densely glandular-setose and pubescent, slightly expanded upwards; bracteoles 2, basal, ovate, ca. 1 mm long, brown, deciduous. Calyx tube green, 3.0-3.5 mm long, densely glandular-setose and pubescent, trichomes slightly denser and longer than those on pedicels; limb 1.1-1.2 cm long, densely glandular-setose and pubescent, lobes tinged with carmine, subulate, 7-8 × 1.5-2.0 mm, densely glandular-setose and pubescent outside, pubescent inside, apex acute. Corolla carmine, green at the apex and maroon on angles, tubular, slightly 5-angled, ca. 3.5 × 0.7-0.9 cm, sparsely glandular-setose and pubescent along the upper half of angles outside, glabrous inside; lobes green, spreading, narrowly triangular, 6-7 mm long, glandular-setose and pubescent on midvein outside, nearly glabrous inside. Stamens 10, ca. 3.6 cm long; filaments flat, ca. 2.5 cm long, glabrous; anthers ca. 1.45 cm long, thecae adnate to each other, ca. 4.5 mm long, tubules ca. 1 cm long, without spurs on the back. Style slender, 3.8-4.0 cm long; stigma truncate; ovary 10-pseudoloculed, each locule with several ovules; disk glabrous. Young fruit green, subglobose, densely glandular-setose and pubescent, with erect persistent calyx lobes at apex.

Etymology.

The species epithet is named in honor of Ms. Jiang-Hai He, a local staff in Huanglian Shan National Nature Reserve, who has worked there for almost 30 years and made a big contribution to the knowledge of biodiversity of this nature reserve, and is also the discoverer of this new species.

Vernacular name.

疆海树萝卜 (Chinese pinyin: Jiāng hăi shù luó bo).

Distribution and habitat.

This species is currently known only from the type locality, i.e. Huanglian Shan National Nature Reserve, Yunnan, China. Since this locality is very close to the border of China and Vietnam and the habitat is similar and continuous, this species is probably also distributed in Vietnam. It grows on the trunks of trees like Schima wallichii (DC.) Korth. or Lithocarpus sp. under broadleaved forests at an elevation of ca. 1800 m.

Conservation status.

Agapetes heana seems to be very rare in the type locality, since only a population of fewer than 10 individuals has been found for now, but the threat risk seems to be low because it is not economically valuable and the conservation condition of the reserve is good. Because no population assessment of this species in the field of China or adjacent area of Vietnam has been made, it is best classified as 'Data Deficient’ (DD) ( IUCN Standards and Petitions Committee 2019).

Additional specimens examined.

(paratypes) The same locality as holotype, 8 April 2021 (young fruits), J. D. Ya et al. 21CS20738 (KUN, IBSC) .

Figures

Figure 1. Agapetes heana A habit B tubers C flowering branch D inflorescence E fruiting branch F fructescence with young fruits (C, D from J. H. He 210304, A, B, E, F from J. D. Ya et al. 21 CS 20738). All photographs by J. D. Ya except C by J. H. He.

Figure 2.. Agapetes heana A fruiting branch B trichomes on branch and petiole C flower D calyx and style E opened corolla, abaxial view F stamens, abaxial (left) and adaxial (right) view G young fruit (A, G from J. D. Ya et al. 21 CS 20738, B-F from J. H. He 210304). Drawn by Mr. D. H. Cui.