Agapetes hongheensis Y. H. Tong & C. Y. Zou, 2025

Agapetes hongheensis Y. H. Tong & C. Y. Zou sp. nov.

Fig. 1 View Figure 1

Type.

China • Yunnan, Honghe Hani and Yi Autonomous Prefecture, Yuanyang County, Ezha Town, Yanjia Village , epiphytic on trees in the forest, elevation 1872 m, 12 Sep 2023, C. Y. Zou & J. Q. Huang ZCY 5280 (holotype: IBK!; isotype: IBSC!) .

Diagnosis.

Agapetes hongheensis is similar to A. mannii Hemsl. (Fig. 2 View Figure 2 ) and A. hosseana Diels , but differs from the former by its linear or narrowly oblong and bullate leaf blade with a strongly recurved margin (Fig. 1 B, C View Figure 1 ) and obvious reticulate veinlets adaxially (Fig. 1 J, K View Figure 1 ), and larger flowers with yellow green and glabrous internal surface of the corollas, and can be distinguished from the latter by having glabrous twigs, linear or narrowly oblong leaf blades, yellow green corollas and exerted style.

Description.

Shrubs epiphytic, ca. 2 m tall. Root tubers spindle-like or globose, 20–30 cm in diameter. Stems erect. Twigs slightly angled, glabrous. Leaves spirally alternate, often crowded at the apex of branchlets; petiole ca. 1 mm long, glabrous; leaf blade linear or narrowly oblong, 3.0–5.5 × 0.5–1.0 cm, length width ratio 4.95 / 1, leathery, glabrous, adaxially bullate, midvein raised on both surfaces, lateral veins raised, veinlets conspicuous, abaxially smooth, base cuneate, apex rounded, margin recurved, entire. Flowers solitary or 2, axillary or on old leafless stem; bracteoles 2, basal, triangular, ca. 0.8 mm long, glabrous; pedicles dark red, 7–11 mm long, expanded upwards, glabrous or sparsely pubescent. Calyx tube pastel red, ca. 3 mm long, sparsely pubescent; limb divided nearly 1 / 3; lobes triangular, ca. 2 × 1.5 mm, apex acute. Corolla yellowish green, tubular; tube 1.9–2.3 cm long, glabrous on both sides; lobes recurved, triangular, ca. 2 mm long. Stamens 10, 1.8–1.9 cm long; filaments flat, 1.2–1.3 cm long, densely pubescent; anthers ca. 6 mm long; thecae ca. 3 mm long; tubules ca. 3 mm long, with 2 erect spurs, spurs ca. 2 mm long. Style glabrous, 1.8–2.3 cm long, exerted from corolla; stigma punctate. Berries globose, almost glabrous, bright red to purple when ripe, 5–8 mm in diameter.

Phenology.

Agapetes hongheensis is known to flower in September-October and fruit in January the next year.

Etymology.

The species epithet denotes where it was found, viz. Honghe Hani and Yi Autonomous Prefecture.

Distribution and habitat.

This new species is known only from the type locality, i. e. Yuanyang County, Yunnan Province, China. It grows on the trunks of trees like Phoebe macrocarpa C. Y. Wu in evergreen broad-leaf forests at an elevation of 1900 m.

Similar species and notes.

Agapetes hongheensis is assigned to Agapetes ser. Longifiles Airy Shaw (1935: 25) , which is characterized by fasciculate inflorescence or solitary flower, and elongated filaments longer than anthers and spurred anther ( Airy Shaw 1935, 1959). In the ser. Longifiles, except our new species, only two other species, viz., A. mannii and A. hosseana , have leaf blade with a round apex and tubular corolla with a glabrous external surface. These two species can be easily distinguished from our new species due to their very distinct morphology of the leaf blade and twigs, and corolla color and length. A more detailed comparison among these morphologically similar species is presented in Table 1 View Table 1 .

We also tried to perform a microscopic comparison of leaf epidermis and pollen exine sculpture morphology of A. hongheensis (Fig. 3 A – D View Figure 3 ) and A. mannii (Fig. 3 E – H View Figure 3 ). The midveins of both Agapetes hongheensis and A. mannii are prominently elevated adaxially and abaxially. The veinlets of A. hongheensis are distinctly raised adaxially and form a reticulate pattern (Figs 1 J, K View Figure 1 , 3 C View Figure 3 ), while the veinlets of A. mannii are not obvious (Figs 2 F, G View Figure 2 , 3 G View Figure 3 ). The pollen grains of Agapetes hongheensis are sub-spheroidal tetrahedral tetrads with a diameter of 36.81 ± 1.47 μm, and the ornamentation of both apocolpium and mesocolpium are granulate (Fig. 3 A, B View Figure 3 ). By comparison, the tetrads of A. mannii are of a smaller size, averaging 35.53 ± 1.54 μm in diameter, with a similar granulate ornamentation on both apocolpium and mesocolpium (Fig. 3 E, F View Figure 3 ). There seems to be little difference between the two species on pollen exine sculpture.