Hemiboea albiflora X.G.Xiang, Z.Y.Guo & Z.W.Wu, 2019

Wu, Zhaowen, Guo, Zhiyou, Deng, Chaoyi, Li, Zhenyu & Xiang, Xiaoguo, 2019, Hemiboea albiflora, a new species of Gesneriaceae from Guizhou, China, PhytoKeys 122, pp. 79-86 : 81-83

Hemiboea albiflora X.G.Xiang, Z.Y.Guo & Z.W.Wu sp. nov. Figs 2 , 3

Type.

China. Guizhou: Xingyi City, Maling River Valley, 26°8.47'N, 104°57.27'E, altitude 967 m, on rock faces near the river, 12 October 2017, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017061 (holotype: PE!; isotypes: PE!, QNUN!).

Diagnosis.

H. albiflora differs significantly from H. gamosepala by its 5-parted calyx from the base (vs. 5-lobed from middle), longer peduncle, 3-6 cm (vs. 0.2-0.4 cm), white corolla (vs. pink corolla) and longer pistil, 2-2.5 cm (vs. ~ 1.5 cm). After extensive observations, Hemiboea albiflora is close to H. cavaleriei var. paucinervis W. T. Wang et Z. Y. Li and H. subcapitata C.B. Clarke, but differs from them through its longer petiole, 3-6 cm; larger involucre, 2-3 cm in diameter; white corolla, glabrous outside; and longer staminal filaments, 1.8-2 cm long. The detailed morphological comparisons are listed in Table 1 .

Description.

Perennial herbs. Stems ascending, subterete, 40-100 cm tall, 2-5 mm in diameter, simple, sparsely purple-spotted, glabrous, juicy when fresh, nodes 5-10, not swollen. Leaves opposite, herbaceous; petiole 3-6 cm long, about 2 mm in diameter, almost terete, adaxially valleculate, margin erect and rounded, glabrous, green; leave blade oblong-lanceolate or ovate-lanceolate, 7-15 cm long, 3-5.5 cm wide, apex acuminate, rarely acute, margin repand-crenate, base usually oblique, adaxial surface green, sparsely pubescent, abaxial surface pale green, glabrous; lateral veins 5-9 on each side of midrib. Cymes subterminal, sometimes axillary, 4-8-flowered; peduncle 2-3 cm long, 3-4 mm in diameter glabrous, sparsely purple-spotted; involucre subglobose or broad ovoid, 2-3 cm in diameter, yellow-green, glabrous, apex acute. Pedicel 3-5 mm long, 2-3 mm in diameter, glabrous. Calyx white, 5-parted from the base, lobes equal, ovate-lanceolate, 1.2-1.6 cm × 0.3-0.4 cm, glabrous. Corolla white, with mauve lines and spots inside, 4-5.5 cm long, glabrous. Corolla tube 3.5-4.5 cm long, 1-1.4 cm in diameter at the mouth, 4-5 mm in diameter at the base, purple-spotted at throat, densely glandular-pubescent inside adaxial gibbous side of the tube, inside with a ring of hairs adnate to 7-8 mm above the corolla tube base; limb 2-lipped; adaxial lip 0.8-1.0 cm long, 2-lobed at apex, lobes equal, nearly semi-orbicular, abaxial lip 1-1.2 mm long, 3-parted, lobes subequal, oblong. Stamens 2, anthers fused by adaxial surfaces, adnate to 0.8-1 cm above the corolla base; filaments linear, glabrous, geniculate from the middle, 1.8-2 cm long, about 1 mm wide; anthers ovate-elliptic, glabrous, ca. 2-3 mm long, 2 mm wide, coherent at apex. Staminodes 2, glabrous, adnate to 1.2-1.5 cm above the corolla base, thick, 1.2-1.4 cm long, about 1 mm wide, apex capitellate, separate. Pistil 2-2.5 cm long; ovary linear, 0.7-0.9 cm long, 1.5-2.2 mm in diameter, glabrous; style 1.3-1.6 mm long, glabrous; stigma capitate, about 2 mm in diameter. Capsule linear-lanceolate, 2-3 cm long, 2-4 mm in diameter, glabrous, slightly curved.

Distribution and habitat.

Hemiboea albiflora is known from Maling River Valley and Pogang Nature Reserve, Xingyi City, Guizhou, China, growing on rock faces near Maling River and near streams in Pogang Nature Reserve, at an elevation of ca. 720-970 m.

Phenology.

Flowering occurs in August to October and fruiting in October to November.

Etymology.

The specific epithet refers to the corolla colour of this new species.

Additional collection.

CHINA. Guizhou: Xingyi City, Maling River Valley, ca. 950 m alt., 12 October 2018, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017060 (PE), X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017062 (PE); Xingyi City, Maling River Valley, ca. 720 m alt., 12 October 2018, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017057 (PE); Xingyi City, Maling River Valley, C.Y. Deng 3071 (XIN); Xingyi City, Pogang Nature Reserve, ca. 1000 m alt.,11 October 2018, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017054 (PE), X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017055 (PE), X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017056 (PE).

Figures

Figure 2. Hemiboea albiflora. A Adaxial leaf blade B flower side view C abaxial leaf blade D flower face view E stem and petioles F opened corolla showing stamens, staminodes and pistil G flowering habit H fruits. Photographs by Zhiyou Guo.

Figure 3. Hemiboea albiflora. A Flowering habit B involucre C root D capsule E calyx segments F stamens G staminodes H pistil I flower inside view. Drawn by Zhaowen Wu.