Geum sunhangii D.G. Zhang, T. Deng, Z.Y. Lv & Z.M. Li, 2020

Lv, Zhen-Yu, Zhang, Dai-Gui, Huang, Xian-Han, Wang 5, Heng-Chang, Yang 6, Jing-Yuan, Tojibaev, Komiljon, Deng, Tao & Li, Zhi-Min, 2020, Geum sunhangii (Rosaceae), a new species from Hubei Province, China, PhytoKeys 156, pp. 113-124 : 113

Geum sunhangii D.G. Zhang, T. Deng, Z.Y. Lv & Z.M. Li sp. nov. Figures 1 , 2

Type.

China. Hubei Province: Shennongjia National Nature Reserve, Nantianmen, alt. 2821 m, 11 July 2011, zdg 7313 (holotype: KUM!)

Diagnosis.

Geum sunhangii and G. aleppicum are most similar in morphology. However, G. sunhangii differs significantly from G. aleppicum by the entire or 3-lobed cauline leaf (vs. blade pinnate, sometimes repeatedly lobed), reniform radical leaf terminal leaflet (vs. rhombic-ovate or compressed orbicular), nodding flowers (vs. erect), imbricate petals (vs. induplicate), curved at the obtuse or right angle at joint (vs. twisted), joint at ca. 2/3 of style apex (vs. ca. 1/4 way from apex). Detailed comparison information is in Table 1 .

Description.

Roots fascicled, taproot terete, ca. 0.7 cm in diameter. Stems erect, 20-60 cm tall, pilose. Radical leaves lyrate-pinnate, 10-25 cm, with 2-4 pairs of leaflets, strigose; leaflets unequal, terminal leaflet largest, reniform, lobed, 2.5-6 × 3-10 cm, base cordate or truncate, margin irregularly coarsely serrate, apex rounded; cauline leaf ovate, herbaceous, 2-2.5 × 2.5-3.5 cm, leaf-like, leaf simple, entire or 3-lobed, margin irregularly coarsely serrate; veins bulge at leaf abaxially. Inflorescence terminal, corymb, bisexual, usually nodding, laxly 2-5 flowered. Flower actinomorphic, ca. 2.3 cm in diameter, pedicel densely pubescent and pilose; sepals triangular-ovate, green, apex acuminate; epicalyx elliptic or lanceolate, minute, ca. 1/3 as long as sepals, apex acuminate. Petals 5, yellow, imbricate, suborbicular, longer than sepals. Stamens numerous, yellow, ca. 0.22 cm; filament linear; anther yellow, ellipsoid. Style terminal, ca. 0.24 cm in length, curved at an obtuse or right angle at joint, joint at ca. 2/3 of style apex, style glabrous and apex separating from joint at fruit maturity. Infructescence ovoid or ellipsoid, ca. 80 seeds; fruiting receptacle hirtellous; achenes hirtellous, hair ca. 0.3 mm, erect (Figs 1 , 2 ).

Phenology.

G. sunhangii flowers in May and sets fruit in August.

Distribution and habitat.

Geum sunhangii is currently found in Nantianmen, Shennongjia National Nature Reserve, Hubei Province (Fig. 6 ). It grows on hillside meadows near water.

Conservation status.

Based on the results of field investigations, Geum sunhangii was only discovered in Nantianmen, Shennongjia National Nature Reserve, where there is almost no human pressure on the distribution location of this species. About 60,000 individuals were present and the extent of occurrence is ca. 30,000 m2. It is possible that additional populations may be discovered during future excursions. We initially define the category of G. sunhangii as Near Threatened (NT) by the Guidelines for Using the IUCN Red List Categories and Criteria ( IUCN 2017).

Vernacular name.

神农花, shén nóng huā in Chinese Pinyin.

Etymology.

The new species is named after the famous Chinese botanist Hang Sun, who made significant contributions to plant taxonomy, floral identification and biogeography in China.

Figures

Figure 1. Images of Geum sunhangii. A Habitat B habit C cauline leaves D radical leaves E roots F corolla G sepals H infructescences.

Figure 2. Holotype of Geum sunhangii. A Plant B achene C gynoecium D cauline leaf E petal F florets G filaments and anthers H calyx. Drawn by Ling Wang.

Figure 6. Distribution of Geum sunhangii in Hubei Province, China. Star indicates the type locality of G. sunhangii.