Saxifraga damingshanensis W.B.Liao, W.Y.Zhao & J.H.Jin, 2019

Zhao, Wan-Yi, Meng, Kai-Kai, Fan, Qiang, Jin, Jian-Hua & Liao, Wen-Bo, 2019, Saxifraga damingshanensis (S. sect. Irregulares, Saxifragaceae), a new species from Guangxi, China, PhytoKeys 133, pp. 95-103 : 95

Saxifraga damingshanensis W.B.Liao, W.Y.Zhao & J.H.Jin sp. nov.

Type.

China. Guangxi: Nanning city, Damingshan Nature Reserve, Longtou Peak, 23°22'58.48"N, 108°30'21.56"E, 1542 m alt., 19 September 2018, W.Y.Zhao 1208 (Holotype SYS!; Isotypes SYS!, IBSC!). ( Fig. 2 )

Diagnosis.

Saxifraga damingshanensis is morphologically most similar to S. mengtzeana , but differs by its leaf blade with glandular trichome and purple spots abaxially, short stamens and petal entire.

Description.

Perennial herbs, 15-30 cm tall. Stolons absent. Rhizomes rather short (ca. 0.3-0.7 cm), sparsely glandular trichomes. Basal leaves forming a rosette, petiole 5-15 cm long, fleshy and translucent, sparsely short glandular trichomes (ca. 2 mm); petiole base sheathed, margin with sparsely glandular trichomes; leaf blade rounded or ovate, base cordate to deep cordate, papery or leathery, 2.0-5.7 × 2.5-5.5 cm, apex obtuse, margin inconspicuous 7-15-lobed with sparsely glandular trichomes, lobes entire, adaxially dark green, densely covered glandular trichomes (2.5-4 mm), abaxially grey, sparsely covered with glandular trichomes (1.5-2.5 mm), densely covered with purple spots; palmate veins 7-11, both surfaces inconspicuous. Cauline leaves 1-2, triangular-lanceolate, 5.0-6.0 × 1.5-2.0 mm, margin with sparsely glandular trichomes. Inflorescence paniculate, 15-30 cm long, 10-35-flowered; branches 4-5 cm, sparsely short glandular trichomes (0.5-1.0 mm), 2-6(-8)-flowered; pedicels slender, 1.5-2.5 cm long, sparsely short glandular trichomes (ca. 0.5 mm); bracts linear, 1.5-2.5 × 0.5-0.8 mm, margin with short glandular trichomes. Flowers zygomorphic; sepals 5, spreading, narrowly ovate, 2.0-2.5 × 1.0 mm, apex obtuse, base connate, adaxially glabrous, abaxial surface and margin with sparsely short glandular trichome, becoming denser proximally, 3 veins inconspicuous. Petals 5, white; shortest 3 petals equal, ovate, base with yellow spots, 3-3.5 × 1.5 mm, apex acute, base rounded, triplinerved; the other two petals lanceolate, first longest petal lanceolate, 18-22 × 1.5-2.5 mm, apex acuminate, margin entire, glabrous, 3-veined; second longest petal narrowly ovate, 1.3-1.7 × 0.2 cm, apex acuminate, margin entire, glabrous, 3-veined. Stamens 10, filaments clavate, 3.5-4.5 mm long. Ovary ovoid, 1.5-2.5 mm long; disc obscure; carpels 2, proximally connate about 3/4; styles 2, divergent, 1.5-2 mm long. Capsule ovoid, 4-5 × 3-4 mm. Seeds elongate-ellipsoid, yellowish-brown or dark brown, the two ends slightly bent, ca. 0.6 mm, surface 3-ribbed.

Phenology.

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

Etymology.

The species epithet is based on the mountain name, Damingshan and the Latin suffix, - ensis, of origin, where the new species was collected.

Distribution, ecology and conservation status.

Only three populations of Saxifraga damingshanensis were discovered from Damingshan National Nature Reserve, Guangxi Province. It was observed to grow on damp cliffs and rocks in broad-leaved forests at altitudes between 1300 and 1650 m. Its known localities are well protected and more field investigations are needed to determine its wild distribution. Therefore, we suggest listing the new species as Data Deficient (DD) based on the IUCN Red List Criteria ( IUCN 2019).

Additional specimens examined (paratypes).

China. Guangxi: Nanning city, Damingshan Nature Reserve, Longtou Peak, Blackwood cliff, 23°22'58.48"N, 108°30'21.56"E, 1542 m alt., 19 September 2018, W.Y.Zhao 1209 (SYS!); same locality, 1500 m alt., 19 September 2018, W.Y.Zhao 1210 (SYS!); same locality, 1522 m alt., 19 September 2018, W.Y.Zhao 1211 (SYS!); same locality,1480 m alt., 19 September 2018, W.Y.Zhao 1212 (SYS!); Wuming county, Xiaolu village, Damingshan, 1420 m alt., 26 August 1958, Y.C.Chen 325 (IBK18155!).

Figures

Figure 2. Saxifraga damingshanensis A Habit B whole plant C basal leaves rosette with long petiole, plant cover white trichomes D flower and fruit, pedicel slender with short trichomes, filaments clavate E adaxial leaf surface dark green, sparsely glandular piliferous F abaxial leaf surface grey, sparsely glandular piliferous and purple spotted G petiole with glandular piliferous H rhizomes cover sparsely glandular piliferous, petiole base sheathed I adaxial surface of sheath, glabrous, margin with glandular piliferous J abaxial surface of sheath, upper with sparse glandular piliferous.