Eriobotrya laoshanica W.B. Liao, Q. Fan & S.F. Chen, 2020

Chen, Su-Fang, Meng, Kai-Kai, Guo, Xi-Bing, Zhao, Wan-Yi, Liao, Wen-Bo & Fan, Qiang, 2020, A new species of Eriobotrya (Rosaceae) from Yunnan Province, China, PhytoKeys 146, pp. 61-69 : 61

Eriobotrya laoshanica W.B. Liao, Q. Fan & S.F. Chen sp. nov.

Type.

China. Yunnan Province, Malipo County, Mount Laoshan, in thin forests on the slopes of limestone hills, 22°59.08'N, 104°50.48'E, 1160 m a.s.l., 14 October 2019, Q. Fan 17570 (holotype: SYS; isotypes: IBSC, SYS). (Figs 2 , 3 )

Diagnosis.

This species is similar to E. malipoensis and E. serrata , but differs from them in its leaf shape, indumentum on the lower leaf surfaces, longer petioles, much fewer flowers on the panicle, larger flowers, and other traits.

Description.

Evergreen small tree, 4-10 m tall, much branched; stems 8-25 cm in diameter; branchlets grey-white, terete, glabrous, 6-10 mm in diameter. Leaves spirally inserted on branches and often crowded at tips of branchlets; petioles 2-5 cm long, glabrous; stipules elliptic or ovate-lanceolate, 1-3 × 0.5-1 cm, glabrous, caducous; leaf blades oblong or broad elliptic, 20-40 × 7-12 cm, thickly coriaceous, glabrous, midrib elevated on both surfaces, secondary veins 21-30 pairs, arching slightly and often dichotomous before reaching the margin, elevated on both surfaces margin serrate, apex acute or cuspidate, base cuneate, gradually tapering to the petiole. Inflorescence in terminal panicles, 15- to 30-flowered, 8-15 cm long, 6-10 cm in diameter, with 6-10 lateral racemes, the lowermost laterals in the axils of reduced leaves (often almost entirely consisting of the stipules only), upper ones in axils of bracts, lateral racemes sometimes branched in the lower part of the inflorescence; peduncle and pedicels densely yellow-brown tomentose; bracts ovate-triangular, 1-1.5 cm long, abaxially tomentose, adaxially glabrous or sparsely pubescent; bracteoles subulate or triangular, 3-8 mm long, abaxially densely tomentose, adaxially pubescent. Flowers 2.5-3 cm in diameter. Hypanthium obconical, 4-6 × 5-7 mm, abaxially densely yellow-brown tomentose, 5-lobed, the calyx lobes ovate, 3-5 × 2-4 mm, abaxially densely tomentose, adaxially glabrous; petals white, obovate or rotund, 6-9 × 5-10 mm, shortly clawed, glabrous, margin crisped or irregularly crenulate, apex retuse; stamens 20; flaments 3-6 mm long, glabrous; anthers 1-2 mm long; ovary semi-inferior, the free apex densely villous, ovoid, 2-3 mm across, 3-5-loculed, with 2 ovules per locule; styles 3-5, densely villous, 5-7 mm long, connate at base or fused from base to middle; ovules ovoid or ellipsoid, c. 1 mm across. Pome yellow at maturity, subglobose, 2.5-3.5 cm in diameter, glabrescent, crowned by the persistent calyx lobes forming an apical beak; pericarpium fleshy, ca. 3 mm thick. Seeds (1-) 2 per fruit.

Phenology.

Flowering from September to October, fruiting from November to December.

Etymology.

The specifc epithet refers to Laoshan Mountain, the locality of the type collection.

Distribution and habitat.

Eriobotrya laoshanica is currently known only from two localities in Laoshan Natural Reserve, Malipo County, southeastern Yunnan, China. Here, the species is distributed in thin forests on the slopes of limestone hills at altitudes of 1100-1358 m a.s.l. The common associated tree species include Aucuba chinensis , Caryodaphnopsis tonkinensis , Ficus semicordata , Firmiana sp., Garcinia paucinervis , Machilus sp. and Syzygium claviflorum .

Conservation status.

Only two populations were found with no more than 50 mature individuals in a total area of about 5 km2. It’s about 6.5 km away between the two populations. The wood of this species is very suitable for firewood. During the expedition in 2019, we found that at least two big trees about 15 cm in diameter were felled by the local villagers. Thus the species could be considered as CR (Critically Endangered) status according to IUCN Red List criteria (B2ab(v); IUCN 2019).

Note.

The closest relative of Eriobotrya laoshanica on morphological grounds could be E. malipoensis Kuan, which usually coexists with the new species. They shared several characteristics, e.g., the long thick-coriaceous leaves that are up to 40 cm long; styles 3-5; and the subglobose fruits. The new species can be distinguished from E. malipoensis , however, by its longer petioles (2-5 vs. 0.5-1 cm); indumentum on the lower leaf surfaces (densely tomentose vs. glabrous); much fewer flowers (15- to 30-flowered vs. 50- to 100-flowered) on the panicle; larger flowers (2.5-3 vs. 1.5-2 cm in diameter); and non-angulated (vs. angulated) young fruits. E. laoshanica also has some resemblance to E. serrata Vidal but differs in its thicker leaves; leaf shape (oblong to broad elliptic vs. obovate to oblanceolate); more lateral veins (21-30 vs. 10-16 pairs); and larger fruits (2.5-3.5 vs. 1.5-1.8 cm in diameter) (Table 1 and Fig. 4 ).

To distinguish these species of Eriobotrya flowering in autumn and winter (from September to February) in China, an identification key is provided (based on Zhang et al. 1990; Gu and Spongberg 2003; Ding et al. 2015).

Additional specimens examined (paratypes).

China. Yunnan: Malipo, Laoshan natural reserve, 22°58.66'N, 104°50.80'E, 1135 m a.s.l., 16 September 2015 (young fl.), Q. Fan 13700 (SYS); the same locality, 16 September 2015 (young fl.), Q. Fan 13701 (SYS); the same locality, 22°59.10'N, 104°50.64'E, 1140 m a.s.l., 30 November 2015 (young fr.), Q. Fan 13887 (SYS); the same locality, 1140 m a.s.l., 30 November 2015 (fr.), Q. Fan 13900 (SYS); the same locality, 1140 m a.s.l., 30 November 2015 (fr.), Q. Fan 13901 (SYS); the same locality, 1160 m a.s.l., 26 September 2019 (young fl.), Q. Fan 17540 (SYS); the same locality, 1358 m a.s.l., 26 September 2019 (no fl. and no fr.), Q. Fan 17543 (SYS).

Figures

Figure 2. Eriobotrya laoshanica sp. nov. A fruiting branch B inflorescence C flower, front view D petal, adaxial view E flower without corolla showing hypanthium and calyx lobes F fruit G fruit, in longitudinal section H fruit, in transverse section. A and F-H from Q. Fan 13900 B-E from Q. Fan 17570. Drawn by Yun-Xiao Liu.

Figure 3. Eriobotrya laoshanica sp. nov. A young flowering branch B reduced leaves and bract C flowering branch D young fruiting branch E fruits F habitat.

Figure 4. Morphological comparisons amongst Eriobotrya laoshanica, E. malipoensis and E. serrata. A-C leaves of E. serrata (A), E. malipoensis (B) and E. laoshanica (C) D-F abaxial leaf surface of E. serrata (D), E. malipoensis (E) and E. laoshanica (F) G, H flowers of E. malipoensis (G) and E. laoshanica (H). Photos taken by Qiang Fan.