Agapetes putaoensis Y.H.Tong & N.H.Xia, 2014

Tong, Yi Hua & Xia, Nian He, 2014, New taxa of Agapetes (Ericaceae) from Myanmar, Phytotaxa 184 (1), pp. 39-45 : 39-41

1. Agapetes putaoensis Y.H.Tong & N.H.Xia , sp. nov. ( Fig. 1 )

S pecies A. lobbii C.B. Clarke (1881: 448) affinis, sed pedunculo brevissimo, lobis calycis triangularibus, 1 mm longis, apice acutis, corolla cylindrico-conica, rubescente, 0.8–1 cm longa, staminibus 0.8–0.9 cm longis differt.

Type:— MYANMAR. Kachin State: Putao, Renan , epiphytic on trees on roadside, 27°42’6”N, 98°2’14”E, elevation 970 m, 15 March 2009 , Ayeyarwady Expedition 2416 (holotype: IBSC!; isotypes: CDBI!, IBSC!) .

Shrubs epiphytic, ca. 1.5 m tall. Twigs longitudinal-striate, glabrous. Leaves spirally scattered; petiole 3–5 mm long, glabrous; blades elliptic-lanceolate, 4–7.5 × 1.5–2 cm, thinly leathery, glabrous, midveins raised on both surfaces, secondary veins 3–5 pairs, with fine veins slightly conspicuous on both surfaces, base attenuate, margin entire, slightly revolute, apex caudate-acuminate. Inflorescences axillary or on leafless stem, 1–5-flowered; peduncle very short, 1–2 mm long; bracts triangular, 0.5 mm long, glabrous; pedicels 1.3–1.7 cm long, glabrous, expanded upwards. Calyx tube white, tubular, ca. 2.5 × 2 mm, glabrous; lobes triangular, ca. 1 mm long, glabrous, apex acute. Corolla reddish white, cylindric-conical, 0.8–1 × 0.2–0.3 cm, glabrous; lobes triangular-lanceolate, 5–6 mm long. Stamens 10, 0.8–0.9 cm long; filaments flat, ca. 1 mm long, margin white pubescent; thecae ca. 2 mm long, papillate; tubules 5–6 mm long, with 2 spurs abaxially, spurs ca. 1 mm long. Style glabrous, ca. 1 cm long; stigma punctate. Fruit not seen.

Distribution and habitat:— This new species is known only from the type locality, Putao, Kachin State ( Figure 4 ). It grows on trees in rainforest at an elevation of 970 m.

Etymology:— The species epithet refers to where it was found.

Conservation status:— This new species was found in Putao County with an area less than 20,000 km 2, and the habitat was being disturbed due to road building, so it may turn out to be Vulnerable ( VU B1 ab(iii)) according to the IUCN Red List criteria ( IUCN 2001 ). However, it is best classified as Data Deficient ( DD) since it was noticed only once in the type locality .

Affinities:— This species is similar to Agapetes lobbii , particularly in the leathery and lanceolate leaves and the half divided corollas, but differs in its very short peduncles (1–2 mm), triangular and shorter calyx lobes (1 mm), smaller flowers (0.8–1 × 0.2–0.3 cm), cylindric-conical reddish white corollas, and shorter stamens (0.8–0.9 cm). Agapetes lobbii has much longer peduncles (0.6–1.25 cm), lanceolate and longer calyx lobes (3–4 mm), larger flowers (2–2.5 × 0.3–0.4 cm), narrowly campanulate crimson corollas and longer stamens (2.3–2.8 cm). Agapetes putaoensis is assigned to Agapetes sect. Agapetes ser. Agapetes subser. Agapetes with its robust stem, thinly leathery and entire leaf and filaments usually shorter than anthers. Although this new species has relatively small flowers for subser. Agapetes , the thinly leathery and entire leaf is the key character to differentiate subser. Agapetes from subser. Chartaceae Airy Shaw (1959: 470).

Pollen morphology:— The pollen grains of Agapetes putaoensis are sub-spheroidal tetrahedral tetrads 29.27 ± 1.86 μm in diameter. Both the apocolpium and mesocolpium ornamentation are granulate ( Fig. 2A & B ). By comparison, the tetrads of Agapetes lobbii are much bigger (41.10 ± 2.20 μm in diameter), and the apocolpium ornamentation is psilate ( Fig. 2C ), while the mesocolpium ornamentation is rugulate ( Fig. 2D ).

Figures

FIGURE 1. Agapetes putaoensis. A. Habit; B. Leafy branch; C. Stamens, abaxial view; D. Stamen, abaxial and adaxial view; E. Opened corolla, abaxial view; F. Calyx and style. From Ayeyarwady Expedition 2416 (IBSC).

FIGURE 2. A−B. The apocolpium ornamentation and the mesocolpium ornamentation of the pollen grains of Agapetes putaoensis, from Ayeyarwady Expedition 2416 (IBSC). C−D. The apocolpium ornamentation and the mesocolpium ornamentation of the pollen grains of Agapetes lobbii, from M. K. Li 1732 (IBSC).

FIGURE 4. Distribution map of Agapetes putaoensis and A. wardii var. heterotricha in Myanmar.