Caltha dysosmoides Tao Zhang, Bing Liu, Y.Q.Hao, Y.Yang & Y.J.Lai, 2016

Liu, Bing, Hao, Yun-Qing, Yang, Yong, Sun, Tian-Tian, Lai, Yang-Jun, Zhang, Tao & He, Fei, 2016, A new species of the Ranunculaceae from southwestern China based on morphological and molecular data, Phytotaxa 283 (1), pp. 43-53 : 48-51

Caltha dysosmoides Tao Zhang, Bing Liu, Y.Q.Hao, Y.Yang & Y.J.Lai , sp. nov. ( Figs. 2 & 3 )

Type:— CHINA. Sichuan: Beichuan County, Piankou Nature Reserve, Zhulingou , 32.218 ° N, 104.221 ° E, elev. 2388 m, 7 May 2013, Tao Zhang, Yun-Qing Hao, Fei He 130501 (holotype, PE; isotypes, PE) .

Diagnosis: — Haec species nova Calthae palustri similis, sed foliis membranaceis reniformibusque, marginibus foliorum dentibus densibus parvisque, pedicellis pendulis, floribus rubris, antheris triangularibus, apicibus connectivorum acutis differt.

Description: —Perennial herbs with numerous fleshy roots. Stems 30–45 cm tall, (2–) 2.5–6 mm diam., divaricately branched, basal leaves 1–2 or absent, long petiolate; petiole (7–) 10–22 cm; leaf blade reniform, membranous, (6–) 8–11 × (8–) 10–15 cm, base cordate to deeply cordate, margin with numerous dense, small serrated teeth, apex obtuse to rounded. Cauline leaves equal to basal leaves in size, or rarely diminishing upward, petiolate or uppermost ones sessile. Monochasium axillary or pseudo–terminal, often solitary, (1 or) 2–3–flowered; flowers pendulous, pedicels 1.8–3 cm long, but becoming erect and more than 5 cm at fruiting. Flowers 1.5–2 cm in diam. Sepals 5, reddish outside and scarlet inside, margin reddish or reddish yellowish, obovate to narrowly obovate, 1.2–1.6(–3) × 0.6–1(– 1.3) cm, apex rounded. Stamens 6–7.5(–8) mm long; filaments oblong, 4–5(–5.5) mm long, compressed, broader than anthers, yellow, anthers sessile or subsessile, connective triangular, 1.5–2 mm long. Carpels numerous, greenish, slightly beaked. Fruit pedicels erect, follicles (9–)11–15, elliptic to ovoid, (10–)12–16 × 2.5–4 cm, compressed, style persistent, 1–2 mm, shortly beaked.

Etymology: —The specific epithet dysosmoides refers to the pendulous inflorescences and the scarlet flowers of the new species, which make it resembles Dysosma ( Berberidaceae ).

Distribution: —This species is only found in a restricted area in northern Sichuan of China ( Fig. 4 ).

Phenology: —It flowers from April to May, and fruits from May to June.

Habitat: —This new species occurs in the herbaceous layer under deciduous broad-leaved forests of mountains with elevation range from 2350 to 2650 m. The dominant tree species of the forest include Quercus spp. ( Fagaceae ), Acer spp. ( Sapindaceae ), trees of Rosaceae such as Photinia sp. , Cerasus sp. and Padus velutina (Batal.) Schneid. , Rhododendron sp. ( Ericaceae ), Davidia involucrata Baill. ( Nyssaceae ), and Litsea pungens Hemsl. ( Lauraceae ). Associated herbaceous species in the community include other species of the Ranunculaceae such as Dichocarpum franchetii (Finet & Gagnep.) W.T.Wang & Hsiao , Anemone flaccida Fr.Schmidt , and Actaea asiatica Hara , species of Apiaceae , i.e. Pternopetalum tanakae (Franch. & Sav.) Hand. -Mazz., P. davidii Franch. , and Sanicula serrata H.Wolff , Caulophyllum robustum Maxim. ( Berberidaceae ), Maianthemum henryi (Baker) La Frankie ( Asparagaceae ), Lathraea japonica Maxim. ex Franch. & Sav. ( Orobanchaceae ), Corydalis pseudomucronata C.Y.Wu & al. ( Papaveraceae ), Cardamine multiflora T.Y.Cheo &R.C.Fang ( Brassicaceae ), Primula odontocalyx Pax ( Primulaceae ), Arisaema lobatum Engl. ( Araceae ), Veronica henryi T. Yamaz. ( Plantaginaceae ), Diplazium squamigerum (Mett.) C.Hope ( Athyriaceae ), Peracarpa carnosa Hook.f. & Thomson ( Campanulaceae ), and Polygonum pinetorum Hemsl. ( Polygonaceae ).

Conservation: —There are three small subpopulations with ca. 160 individuals ( Tab. 4), which are sporadically dispersed under the deciduous broad-leaved forest of ca. 6 km 2 (EOO). Fortunately, the primary forests are strictly protected in the nature reserve. The population appears to be stable. Based on IUCN Red List Categories and Criteria ( IUCN 2011), the new species is assessed to be “Critically Endangered” (CR Blab (v) + D).

Additional specimens examined: — CHINA. Sichuan: Beichuan County, Piankou Nature Reserve, Zhulingou, 18 May 2013, Bing Liu, Yun-Qing Hao, Yang-Jun Lai, Fei He 1842 (PE).

Figures

FIGURE 2. Illustrations of Caltha dysosmoides Tao Zhang et al. showing morphological details. A, habit; B, flower; C, androecium and gynoecium; D, follicles; E, stamens showing the compressed filament and the triangular connective.

FIGURE 3. Morphology of Caltha dysosmoides Tao Zhang et al. A. habit in flowering period; B. flowering branch; C. inflorescence; D. flower. arrow (a) showing stamen; E. androecium and gynoecium. arrow (a) showing stamen and (b) showing carpel; F. fruiting branch; G. habit in fruiting period; H. aggregate fruit, arrow (c) showing follicles.

FIGURE 4. Distribution map of Caltha dysosmoides Tao Zhang et al.