Eriobotrya shanense D.H. Kang, H.G. Ong & Y.D. Kim, 2021

Kang, Dae-Hyun, Ong, Homervergel G., Lee, Jung-Hoon, Jung, Eui-Kwon, Kyaw, Naing-Oo, Fan, Qiang & Kim, Young-Dong, 2021, A new broad-leaved species of loquat from eastern Myanmar and its phylogenetic affinity in the genus Eriobotrya (Rosaceae), Phytotaxa 482 (3), pp. 279-290 : 281-285

Eriobotrya shanense D.H. Kang, H.G. Ong & Y.D. Kim , sp. nov. ( Figs. 1 & 2 )

Type: — MYANMAR. Southern Shan State, Ywangan Township , N21° 14’ 59.9” E96° 25’ 43.7”, elev. 1,422 m, 01 Jan. 2017, Kim et al. MM-6026 (holotype HHU barcode 880000016009; isotypes HHU barcode 880000016016, KB barcode 880000016023, RAF barcode 880000016030) .

Diagnosis:—Leaf morphology of Eriobotrya shanense is similar to that of E. malipoensis and E. japonica by having tomentose hairs on the abaxial surface of its blade but can be differentiated by its obovate, widely obelliptic or oval blade shape, its length-width ratio of 2:1 (vs. 3:1), and rounded or obtuse apex (vs. acute). The species also resembles less-known, undercollected Myanmar broad-leaved species E. wardii and E. platyphylla in leaf shape and length-width ratio, but can be easily differentiated by the presence of tomentose hairs on the leaves and inflorescence. See Table 1 for a detailed comparison.

Description:—Trees to 8 m tall, evergreen, much-branched. Branchlets terete, stout, grayish to dark gray, roughened and marked by leaf scars, glabrous. Leaves simple, helically alternate, clustered at tips of branchlets; stipules paired, connate from base to below apex, adnate to petiole, triangular-hastate or subulate, 5–8 × 4–6 mm, apex shortly notched, margin incised-serrate or entire, rustic brown tomentose abaxially, caducous; petiole short, 3–5 mm long, brown tomentose, becoming glabrescent; leaf blades obovate, widely obelliptic or oval, 10–26 × 5–13 cm, dark green and leathery, base cuneate, margin remotely obtusely serrate, apex rounded or obtuse, midvein prominent, raised abaxially, lateral veins 14–20 pairs, usually branching before terminating at margin, abaxial surface grayish tomentose, brownish tomentose along veins, adaxial surface glabrescent to glabrous at maturity, lustrous. Inflorescence in terminal panicles, 30 to 80-flowered, ca. 16 × 12 cm; peduncle densely rustic brown tomentose; bracts lanceolate, 8–10 mm long, densely rustic brown tomentose abaxially; bracteoles narrowly lanceolate, 5–8 mm long, densely rustic brown tomentose abaxially; pedicels 2–8 mm long, brown tomentose, becoming gray and glabrescent at fruit. Flowers bisexual, actinomorphic, 1.5–2 cm in diam., fragrant; hypanthium shallowly cupular, ca. 2 mm long, slightly 5-ribbed, brown tomentose abaxially; sepals 5, connate and continuous with the hypanthium; sepal lobes ovate, 3–4 mm long, greenish, brown tomentose abaxially, spreading at anthesis, becoming strongly reflexed, persistent; petals 5, distinct, white, asymmetrically orbicular or obovate, 6–9 × 5–7 mm, base not clawed, apex obtuse or emarginate, glabrous; stamens 20, connate at base forming a ring, exserted; filaments ca. 4 mm long, white, glabrous; anthers dorsifixed, dithecal, ca. 1 mm long, light yellow with whitish connective, dehiscing longitudinally; pistil 1, syncarpous; ovary half-inferior, 3–5 locular, rhomboid, exposed portion less than 1 mm long, placentation axile, densely woolly apically; ovules 2 per locule; styles 3–5, connate at base, erect, 3–4 mm long, glabrous, densely woolly basally; stigma truncate. Fruit a pome, asymmetrically obovoid or ellipsoid, 1–2.5 × 1–2 cm, green and brown tomentose when young, becoming yellow and glabrescent at maturity, crowned with persistent sepals. Seeds 1–3(4) per fruit.

Phenology:—The species was observed to be flowering from December to February, and fruiting until May or June.

Etymology:— Eriobotrya shanense is named after its type locality, Shan State in eastern Myanmar.

Distribution and habitat:— Eriobotrya shanense is known to be narrowly distributed in its type locality, Ywangan Township in southern Shan State. So far, two populations have been found, one consisting of not less than 10 fullgrown trees, and the other of ca. 20 mature and juvenile individuals. The tree grows on slopes of irregularly rocky limestone karst hills, along with Firmiana kerri (Craib) Kostermans (1961: 389) , Sterculia villosa Roxburgh (1832: 153 , 154), Wightia speciosissima (D. Don) Merrill (1938: 67) , Bauhinia variegata Linnaeus (1753: 375) , Ceratostigma asperrimum Stapf ex Prain (1906: 6 , 7), and Trichodesma calycosum Collett & Hemsley (1890: 92 , 93).

Conservation status:—The species can be seen thriving along a trail up a Buddhist pagoda/stupa and can (still) be observed growing near a hillside village and farm area, despite having no apparent economic value, except maybe as firewood. It may, therefore, be categorized as Vulnerable (VU) according to the IUCN category ( IUCN 2019).

Additional specimens examined (paratypes):— MYANMAR, Southern Shan State, Ywangan Township , N21° 15’ 13.5” E96° 25’ 50.8”, elev. 1,517 m, 02 Feb. 2018, Kim et al. MM-6665 (4 sheets, HHU) ; N21° 15’ 14.7” E96° 25’ 49.9” 1,530 m, 02 Feb. 2018, Kim et al. MM-6671 (4 sheets, HHU) ; N21° 15’ 12.8” E96° 25’ 51.7” 1,513 m, 26 Jun. 2019, Kim et al. MM -7165 (2 sheets, HHU) ; N21° 15’ 12.8” E96° 25’ 51.7” 1,513 m, 26 Jun. 2019, Kim et al. MM- 7170 (7 sheets, HHU) ; N21° 14’ 28.5” E96° 26’ 11.8” 1,469 m, 01 Jul. 2019, Kim et al. MM-7352 (2 sheets, HHU) ; N21° 14’ 28.5” E96° 26’ 11.8” 1,469 m, 01 Jul. 2019, Kim et al. MM-7353 (3 sheets, HHU) ; N21° 14’ 28.5” E96° 26’ 11.8” 1,469 m, 01 Jul. 2019, Kim et al. MM-7365 (1 sheet, HHU) ; N21° 14’ 28.5” E96° 26’ 11.8” 1,469 m, 01 Jul. 2019, Kim et al. MM-7366 (1 sheet, HHU) ; N21° 14’ 27.1” E96° 26’ 15.6” 1,493 m, 02 Jul. 2019, Kim et al. MM-7385 (1 sheet, HHU)

Figures

FIGURE 1. Eriobotrya shanense D.H. Kang, H.G. Ong & Y.D. Kim A. Flowering branch B. Leaf blade C–D. Stipules E. Bract F–G. Flower abaxial and adaxial view H–I. Petals J. Flower longitudinal section showing the androecium and gynoecium K. Stamen L. Styles and exposed ovary M. Ovary cross section N. Fruiting branch O–P. Fruit cross and longitudinal section. A–M. from Kim et al. MM-6026 (holotype HHU). Illustration by Ye-Seul Jang.

FIGURE 2. Eriobotrya shanense D.H. Kang, H.G. Ong & Y.D. Kim. A. Habitat B. Stipule and petiole C. Inflorescence D. Flower E. Petals (base not clawed) F. Fruiting branch.