Polygala qii X. L. Yu, J. J. Zhou & A. Liu, 2024

Liu, Ang, Zhou, Jian-jun, Li, Xiong, Yu, Xun-lin & Wu, Lei, 2024, Polygala qii, a new species of Polygalaceae from limestone landform in Southern Hunan, China, PhytoKeys 244, pp. 77-87 : 77-87

Polygala qii X. L. Yu, J. J. Zhou & A. Liu sp. nov.

Figs 1 , 2

Diagnosis.

This new species is similar to P. fallax Hemsl. and P. arillata Buch. - Ham. & D. Don, but it differs from the latter two in having erect and shorter inflorescences (0.2–1 cm VS 10–15 cm VS 7–10 cm) and fewer flowers (1–5 flowers VS 10–30 flowers VS 10–20 flowers). Its caruncle is foam, and the latter two are helmeted in shape. Please refer to Fig. 3 and Table 1 .

Type.

China. Hunan: Yongzhou City, Dao County, Yueyan Forest Farm, in the crevices of dry limestone, elevation ca. 290 m, 25 March 2021, Ang Liu DX 01 (Holotype CSFI!, isotype CSFI!, HIB!). Please refer to Fig. 4 .

Description.

Shrubs, 0.5–1.5 m high. Branchlets yellow, sparsely pilose, and the branch bark is cracked into irregular thin scales, especially on the specimens. Leaves alternate, clustered at the top of branchlets. Petiole ca. 1 cm, pubescent. Leaf blade papery, elliptic to oblong elliptic, 5–11 × 2–5 cm, with membranous transparent edge, full margin, ciliate, both sides sparsely pubescent, dense along the veins, then gradually glabrous, midvein raised abaxially, depressed adaxially, lateral veins 5 or 6 pairs, apex acuminate or short tail tip, base cuneate or obtuse. Racemes opposite to leaves, with 1–5 flowers, erect or slightly drooping at the apex, densely pubescent, 0.2–1 cm long, up to 5 cm at fruiting. Pedicel glabrous, ca. 0.5 cm long, to 1 cm at fruiting. Flowers 1.6–2.3 cm. Sepals 5, ciliate, fall off after flower, outer 3 small, unequal in size, upper 1 deep pocket shaped, 0.5 cm long, lateral 2 oval, ca. 0.3 cm long, inner sepals 2, petal shaped, yellowish white, obliquely obovate, edge rolled in a boat shape, 1.5–2 cm, and at right angles to the petals. Petals 3, connate in lower 2 / 3, yellowish white, with light purplish red at the apex, slightly fleshy; keel longer than lateral petals, apex with multifid appendages, appendages with short stalks at the base, ca. 0.15 cm. Stamens 8; filaments ca. 1.5 cm, lower 2 / 3 united, forming an open staminal sheath, adnate with petals; anthers ovoid. Disk fleshy. Ovary round, flattened, ca. 0.4 cm, glabrous, style ca. 1.5 cm, bent to the top, with knee bending at 2 / 3, and obviously expanded to the apex in a trumpet shape. Capsules green, baccate, broadly reniform or slightly cordate, ca. 1 cm, margin winged, ciliate, apex emarginate, mucronate. Seeds globose, sparsely white pubescent, caruncle foam.

Phenology.

Flowering from late March to mid-April; fruiting from late April to early May. What is very special is that this new species enters a dormant period with leaf withering in mid-July.

Etymology.

The new species is named after Professor Cheng-jing Qi ( CSUFT & CSFI), who has made great contributions to the study of Hunan flora ( Qi & Yu, 2002).

Vernacular name.

The Chinese name of the new species is ‘ 石山远志’, and the pronunciation of the Chinese Pinyin is ‘ shí shān yuǎn zhì’.

Distribution and habitat.

This new species is currently only found in the limestone landform areas of Dao County and Ningyuan County, which usually grows in the crevices of dry limestone.

Additional specimens examined

(Paratypes). China. Hunan: Yongzhou City, Dao County, Yueyan Forest Farm, in the crevices of dry limestone, elevation ca. 250 m, 22 April 2020, Xiong Li & Ang Liu LK 0421 ( CSFI!, HIB! & CSH!); Yongzhou City, Ningyuan County, Jiuyi Mountain, in the crevices of dry limestone, elevation ca. 300 m, 29 April 2020, Jian - jun Zhou NY 005 ( CSFI!). Please refer to Figs 5 , 6 .

Conservation status.

At present, we have only found two populations with a total of about 30 individuals in the limestone areas of Dao County and Ningyuan County. However, there are vast limestone landforms in southern Hunan, and there may be distribution of this new species in these areas. Of course, we need a broader and deeper investigation to confirm that. According to the IUCN red list criteria ( IUCN 2022), the conservation status of the new species should be better categorized as ‘ Data Deficient ( DD) ’.

Figures

Figure 1. Polygala qii sp. nov. A habit B plant C plant D branch with flowers E inflorescence F front view of flowers G infructescence H capsules and Seeds. Photographed by Ang Liu.

Figure 2. Polygala qii sp. nov. A branches with flowers B top view of flower C side view of flower D anatomical structure of flower, sepals, petals and pistil E longitudinal section of flower F infructescence G capsule H seed. Drawn by PhD Jing Tian.

Figure 3. Morphological comparison between Polygala fallax (A 1 – A 3), Polygala qii sp. nov. (B 1 – B 3), Polygala arillata (C 1 – C 3). A 1, B 1, C 1 inflorescence A 2, B 2, C 2 infructescence A 3, B 3, C 3 seeds, the red arrow represents caruncle. C 2, C 3 photographed by Xin-xin Zhu, others photographed by Ang Liu.

Figure 4. Holotype of Polygala qii sp. nov. (Ang Liu DX 01, CSFI 076291).

Figure 5. Paratype of Polygala qii sp. nov. (Xiong Li & Ang Liu LK 0421, CSFI 076288).

Figure 6. Paratype of Polygala qii sp. nov. (Jian - jun Zhou NY 005, CSFI 080027).