Ohwia luteola (H. Ohashi & T. Nemoto) H. Ohashi

Ohwia luteola (H. Ohashi & T. Nemoto) H. Ohashi View in CoL

Fig. 6 View Figure 6

Diagnosis.

Ohwia luteola resembles O. caudata but differs from the latter by having terminal leaflets length / width ratio rang from 2.9 to 3.6 (vs. terminal leaflets length / width ratio rang from 4.2 to 6.7), leaflets apex acute (vs. acuminate) terminal inflorescences (vs. terminal and axillary), wings with distinctly auriculate at base, inner side indistinctly rugose (vs. wings with slightly auriculate at base, inner side distinctly rugose), hilum center, not over 3 / 5 length of seed (vs. hilum off-center, over 1 / 2 length of seed).

New record.

Populations of Ohwia luteola are known from Xixiping Street, Yaping village, and Bamaoxi village of Zhangjiajie. It is growing on limestone along the Lishui River. The companion species mainly including Adina rubella Hance, Distylium buxifolium (Hance) Merr. , and Cornus quinquenervis Franch.

Specimens examined.

China • Hunan: Zhangjiajie City, Yongding District, Sanjiaguan Township, Yaping village, under Zhanghua Lishui Large Bridge , on limestone areas along Lishui River, alt. 218 m, 29.111375 ° N, 110.258679 ° E, 31 Aug. 2023, M. H. Zhang et al. 0029 ( JIU) GoogleMaps ; • Yunnan: Jinping County, Laomeng River , alt. 750 m, 20 May 1974, Lüchun Exped. 944 ( KUN 0608532 About KUN ) ; • Yiliang County, Niujie , alt. 450 m, 23 Sep. 1972, Northeast Yunnan Exped. 928 ( KUN 0608538 About KUN ) .

Revised description.

Shrubs, erect, 1–2 m tall, main stem ca. 1 cm in diam at base, much branched. Leaves 3 - foliolate, thickly papery to subleathery, both surfaces pilose and more densely hairy on raised veins, margin entire. Petiole 2–3 cm long, with narrowly winged on both, 0.2–0.3 mm wide. Terminal leaflet oblong-elliptic, widest near the middle part, 4–7.1 × 1.5–2.4 cm, principal veins 10–14 pairs, reaching the leaf margin, apex acute, base cuneate, small petiole 0.8–1.2 cm long, pubescent. Lateral leaflets smaller, 3.7–6.4 × 1.1–1.8 cm, small stipe 0.2–0.3 cm long, widest near the middle part, principal veins 6–12 pairs, reaching the leaf margin, apex acute, base cuneate, small petioles 0.2–0.3 cm long, densely pubescent. Stipules 3–7 mm long, ca. 1.0 mm wide at the base, densely pubescent, persistent. Inflorescences terminal, 7–19 cm long, rachis densely pubescent intermixed with minute uncinate and appressed or spreading longer hairs, 2–4 - flowered at each node; bracts subulate, ca. 0.3 cm long. Pedicels 0.4–0.6 cm long, densely pubescent. Calyx campanulate, 0.8–1.2 cm long, outside densely appressed pubescent, 4 - lobed, lobes united for ca. 1 / 2 length, lobes ca. 0.5 cm long, longest one linear-lanceolate. Corolla greenish-white or yellowish-white, ca. 1.5 cm long, distinctly veined; standard elliptic, 0.8–1.7 × 0.5–1.0 cm, claw ca. 2.5 mm, slightly auriculate at base, apex slightly retuse; wings shorter than keel, 1.3–1.6 cm long, apex obtuse, lamina narrowly elliptic, distinctly auriculate at base, claw ca. 3 mm, keel 0.8–1.8 cm long, apex rounded, slightly auriculate at base, claw ca. 3 mm. Vexillary stamen slightly connate at base from other 9, ca. 1.6 cm long, puberulent at upper part; remaining 9 stamens connate for 4 / 5 or more of length, puberulent at upper part. Style curved upward, ovary densely ap-pressed pilose on both sutures. Disk present at base of pistil. Legume linear, flat, 3.5–7 cm long, stipe ca. 5 mm long, 3–6 - jointed; articles nearly rectangle, 1–1.3 × 0.5–0.7 cm, with dense, transparent to brown, uncinate hairs. Seeds compressed, reniform, ca. 12 × 5 mm; hilum center, not over 3 / 5 length of seed. Flowering from July to early September; fruiting from September to November.

Conservation status.

During our field investigations in 2022 and 2024, many populations of O. luteola were found in Zhangjiajie. The number of individuals of each population ranges from tens to hundreds. In addition, it is distributed along the river. We believe that it should have a much wider distribution than is currently known. Due to its wide distribution range and large population size, O. luteola is here recommended as Least Concern (LC) ( IUCN 2022).