Research Article |
Corresponding author: Yi-Hua Tong ( yh-tong@scbg.ac.cn ) Academic editor: Peter de Lange
© 2021 Yi-Hua Tong, Ying Bai, Jian-Ming Feng, Ji-Dong Ya.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tong Y-H, Bai Y, Feng J-M, Ya J-D (2021) Agapetes heana, a new species of A. ser. Longifiles (Ericaceae) from Yunnan, China. PhytoKeys 180: 133-139. https://doi.org/10.3897/phytokeys.180.69667
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Agapetes heana Y. H. Tong & J. D. Ya (Ericaceae), a new species from Lüchun Xian, Yunnan Province, China is described and illustrated. This new species is assigned to Agapetes sect. Agapetes ser. Longifiles Airy Shaw. It is closest to A. inopinata Airy Shaw and A. oblonga Craib, but differs in having bead-like tubers, leaf blade with a wholly serrulate margin, subulate and much longer calyx lobes, much larger corollas that are carmine, green at the apex and maroon on angles, and longer stamens without spurs on the back.
China-Vietnam border, epiphytic, Huanglian Shan, morphology
A general introduction to Agapetes D. Don ex G. Don, focusing on the species in China was given in previous papers published by the first author and is not repeated here (
Specimens were collected from Huanglian Shan National Nature Reserve, Yunnan Province, China during two field expeditions in March and April 2021, respectively. All descriptions were based on dried specimens, which were deposited at the herbaria of Kunming Institute of Botany, Chinese Academy of Sciences (
China. Yunnan Province: Lüchun Xian, Huanglian Shan National Nature Reserve, elev. 1803 m, 4 March 2021 (fl.), J. H. He 210304 (holotype
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
A morphological comparison among Agapetes heana, A. inopinata and A. oblonga.
Characters | A. heana | A. inopinata | A. oblonga |
---|---|---|---|
Tubers | Bead-like | Spindle-shaped | Spindle-shaped |
Leaf blade margin | Serrulate | Entire | Entire or inconspicuously serrate beyond middle, or sparsely denticulate at apex |
Inflorescence | Shortly racemose, 2–3-flowered | Racemose, 4–6-flowered | Fasciculate, 1–4-flowered |
Calyx lobes | Subulate, 7–8 mm long | Triangular, ca. 1 mm long | Triangular, 1.5–2.0 mm long |
Corolla color | Carmine, green at the apex and maroon on angles | Red | Crimson or carmine |
Corolla length | Ca. 3.5 cm | Ca. 0.8 cm | 1.3–1.9 cm |
Corolla lobes | Narrowly triangular, 6–7 mm long | Triangular, ca. 1 mm long | Triangular, ca. 1.5 mm long |
Stamen length | Ca. 3.6 cm | Ca. 0.7 cm | 1.0–1.5 cm |
Spurs on the back of anthers | Absent | Present | Present |
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.
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.
疆海树萝卜(Chinese pinyin: Jiāng hăi shù luó bo).
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.
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) (
(paratypes) The same locality as holotype, 8 April 2021 (young fruits), J. D. Ya et al. 21CS20738 (
According to Airy Shaw’s infrageneric system, A. heana fits well with the circumscription of Agapetes sect. Agapetes ser. Longifiles Airy Shaw due to its slender stems, flowers arranged into a short raceme, and elongated filaments (longer than anthers) (
We thank Mr. Ding-Han Cui for preparing the line-drawing. This study was funded by the National Natural Science Foundation of China (grant no. 31870180), Biological Resources Program, Chinese Academy of Sciences (KFJ-BRP-017-33), the National Wild Plant Germplasm Resource Center and the Large-scale Scientific Facilities of the Chinese Academy of Sciences.