Paraboea dolomitica Z.Y. Li, X.G. Xiang & Z.Y. Guo, 2020

Guo, Zhiyou, Wu, Zhaowen, Xu, Weibin, Li, Zhenyu & Xiang, Xiaoguo, 2020, Paraboea dolomitica (Gesneriaceae), a new species from Guizhou, China, PhytoKeys 153, pp. 37-48 : 37

Paraboea dolomitica Z.Y. Li, X.G. Xiang & Z.Y. Guo sp. nov. Figs 2 , 3

Diagnosis.

Paraboea dolomitica is morphologically similar to P. filipes . Both of them have obovate leaf blades, 1-4-flowered cymes and a purplish corolla, but P. dolomitica differs from P. filipes by its leathery leaves with denticulate margins (vs. papery leaves with subentire margins in P. filipes ), peduncles sparsely covered with brown hairs (vs. sparsely sericeous-lanate when young and glabrate when mature), two woolly bracts (vs. two glabrous bracts), reniform anthers (vs. oblong anthers), two staminodes 0.3 cm long (vs. 1 staminodes 0.02 cm long), and flowering during April and May (vs. flowering during September and October) (Table 1 ).

Phylogenetic analysis suggested that P. dolomitica was nested in a clade including P. crassifolia (Hemsl.) Burtt, P. tetrabracteata F. Wen, Xin Hong & Y. G. Wei, P. peltifolia D. Fang et Z. Zeng, P. vetutina (W. T. Wang et C. Z. Gao) Burtt, P. dushanensis W. B. Xu & M. Q. Han, P. dictyoneura (Hance) Burtt, P xiangguiensis W. B. Xu & B. Pan and P. guilinensis L. Xu et Y. G. Wei, but P. dolomitica can be easily differentiated from them in leaf position, inflorescence, penduncle, bract and capsule. The detailed morphological comparison of the species most morphologically similar to P. dolomitica is listed in Table 1 .

Type.

China. Guizhou: Shibing County, Yuntai Mountain, 27°06'80.7"N, 108°07'00.0"E, elevation 885 m, on rock faces of a karst dolomite cave, 2 May 2017, Z.Y. Guo 20170047 (holotype: PE!; isotypes: PE!, QNUN!).

Perennial herbs. Rhizomes subterete, 1.5-6.0 cm long, 0.3-0.5 cm diam. Roots slender, fibrous. Leaves crowded near stem apex, opposite; blade leathery, obovate to elliptic, 2.5-4.5 cm long, 1.0-1.5 cm wide, apex acute or rounded, base rounded to broadly cuneate, margin denticulate, involute; adaxial surface with arachnoid covering when young, but glabrescent when mature, abaxially densely brown woolly; principal vein depressed above, raised beneath, lateral veins 3-6 on each side of midrib, tertiary venation inconspicuous; petiole 0.8-2.0 cm long, 0.2-0.3 cm broad, densely covered with appressed velvety hairs. Cymes axillary, umbel-like 1-4-flowered; peduncle 3-5 cm long, 0.05-0.08 cm in diameter, sparsely lanate and glandulose-pubescent. Bracts 2, 0.3-0.4 cm long, linear, woolly beneath; pedicel 0.8-2.2 cm long, 0.05-0.1 cm in diameter, sparsely lanate with glandular hairs. Calyx 5-parted, 0.4-0.6 cm long, 0.1-0.15 cm in diameter, apex acute, densely brown woolly; segments linear. Corolla oblique-campanulate, zygomorphic, purplish, 1.0-1.2 cm long, outside and inside glabrous; tube 0.5-0.6 cm long; throat ca. 0.7 cm in diameter; adaxial lip 2-lobed, lobes orbicular or deltoid, abaxial lip 3-lobed, lobes oblong-elliptic or oblong. Stamens 2, glabrous; filaments 0.5-0.6 cm long, ca. 0.08 cm in diameter, yellow, curved at the upper part; anthers reniform, ca. 0.3 cm long, 0.2 cm broad; staminodes 2, linear, ca. 0.3 cm long. Pistil glabrous, ovary linear, stigma capitate. Capsule linear, 1.5-1.8 cm long, 0.15-0.2 cm broad, glabrous, slightly twisted.

Distribution.

Paraboea dolomitica is known from Yuntai Mountain, Shibing County and Wuyang River, Zhenyuan County, Guizhou, China.

Phenology.

Flowering occurs in April and May and the fruiting occurs between June and August.

Etymology.

The specific epithet refers to the habitat of this new species, the dolomite karst area.

Habitat and ecology.

Paraboea dolomitica grows on rock faces of dolomite karst area, at an elevation of ca. 650-855 m. Accompanying plants in the habitat are sparse and include trees, such as Platycarya strobilacea Sieb. et Zucc., Cotinus coggygria Scop., and herbs such as Selaginella moellendorfii Hieron., Paphiopedilum micranthum T. Tang et F. T. Wang, Viola diffusa Ging., Galium aparine Linn. var. echinospermum (Wallr.) Cuf. and Carex sp.

Additional collections.

China. Guizhou: Zhenyuan County, Wuyang River, 27°06'80.7"N, 108°07'00.0"E, elevation 650 m, on rock faces, 3 August 2016, Guo ZY, GZY1608721 (PE and QNUN), GZY1608723 (PE and QNUN), GZY1608724 (PE and QNUN).

Figures

Figure 2. Paraboea dolomitica. A Habitat B flowering habit C flower face view D opened corolla showing stamens, staminodes and pistil E bracts F pistil with calyx G adaxial leaf blade; and H abaxial leaf blade.

Figure 3. Paraboea dolomitica. A Flowering habit B opened corolla showing stamens, staminode and pistil C pistil with calyx and D capsule. Drawn by Zhaowen Wu based on holotype and isotypes.