Wisteriopsis J.Compton & Schrire, 2019

Compton, James A., Schrire, Brian D., Koenyves 3, Kalman, Forest, Felix, Malakasi, Panagiota, Sawai Mattapha, & Sirichamorn, Yotsawate, 2019, The Callerya Group redefined and Tribe Wisterieae (Fabaceae) emended based on morphology and data from nuclear and chloroplast DNA sequences, PhytoKeys 125, pp. 1-112 : 39-40

6. Wisteriopsis J.Compton & Schrire gen. nov.

≡ Millettia Sect. Eurybotryae Dunn, J. Linn. Soc., Bot. 41: 135 (1912a)

Diagnosis.

The five species of Wisteriopsis (Fig. 5 ) possess a fine ring of hairs lining the inner rim of the calyx cup, prominent gibbosities below the stipules and persistent bracts at the base of pedicels (vs. bracts caducous in Callerya s.str.). Wisteriopsis has glabrous standards (vs. sericeous in Callerya s.str.) and wings equalling or slightly shorter than the keel in length (vs. wings much shorter than the keel in Callerya ). The unique character of this genus is the staminal column being visible between wings and keel at anthesis, becoming free from the keel after pollinator tripping. See under Nanhaia for comparisons with Wisteriopsis .

Type species.

Wisteriopsis japonica (Siebold & Zucc.) J.Compton & Schrire ≡ Wisteria japonica Siebold & Zucc.

Genus description.

Robust twining woody vines attaining 4-18 m in height climbing over shrubs or sprawling over rocks. Stems greyish brown or brown, terete, young branches finely grey or brown tomentose becoming glabrous (or densely ferrugineous tomentose in W. eurybotrya ). Leaves deciduous (in W. japonica ) or evergreen, chartaceous or coriaceous, imparipinnate, rachis 9-20 cm long. Stipules 2-4 mm long, persistent or caducous, emerging from a subulate or mounded gibbosity. Stipels 1-5 mm long, persistent or caducous, petiolules 3-4 mm. Leaflets (5 -) 7-15, in opposite pairs, ovate-lanceolate, elliptic, ovate or ovate-oblong (linear-lanceolate in W. reticulata var. stenophylla ) 15-40 × 5-20 mm, upper surface glabrous with reticulate venation (smooth and shiny in W. championii ), lower surface paler and glabrous or with hairs along veins, apex obtuse, acute, acuminate or cuspidate, margins entire, base cordate or cuneate. Inflorescence 8-40 cm long, laterally paniculate and sometimes racemose in leaf axils, acropetal, erect or pendulous, sparsely hairy or glabrous. Flowers 7-16 mm long emerging from April to August. Floral bracts persistent, (caducous in W. eurybotrya ), linear to subulate, 1-6 mm long, subtending base of pedicel. Bracteoles subtending and adnate to base of calyx, linear, acuminate 1-2 mm long, persistent. Pedicels elongating at flower maturity, 2-8 mm long, glabrous or pubescent. Calyx tubular, cupuliform or campanulate, 1.5-4 × 2-6 mm, glabrous or pubescent externally, with an annulus of fine hairs at the mouth presenting a ciliate margin, five lobed, lobes more or less equal, upper lobes obtuse or deltoid, lower lobes bluntly acute. Standard 6-12 × 4-10 mm, white sometimes flushed pale pink, greenish white, pink or purple, ovate or suborbicular, slightly deflexed backwards near the base, back of standard glabrous, inside with yellow or green nectar guide, callosities of boss type. Wing petals 5-13 × 2-4 mm, equal in length to the keel petals, each semi-pandurate with a short pair of auricles near the base and a prominent basal claw 1-3 mm long. Wing petals free of the keel at time of anthesis. Keel petals glabrous, united into a semi-pandurate cup, base with conjoined parallel claws, apex obtuse (acute in W. eurybotrya ). Stamens diadelphous, nine fused together, the vexillary one free, all curved upwards at apex, staminal column visible between wings and keel at anthesis, becoming free from keel after pollinator tripping (tardily so in W. reticulata ). Ovary glabrous, style 2-3 mm long, curved upwards at apex, stigma punctate. Pods 65-125 × 8-30 mm, linear, ovate or narrowly elliptic, compressed, (inflated in W. eurybotrya ), pale green becoming very dark brown, cartilaginous and tardily dehiscent, exocarp glabrous externally (margins thickened in W. eurybotrya ), surface finely corrugated, endocarp chartaceous, pale cream, detaching tardily from the exocarp, the seeds in hollow cavities, pods dehiscing explosively, the valves opening straight or twisting to release the seeds, subseptate. Seeds (1 –)6– 8, lenticular, suborbicular to oblate-spheroidal, smooth, brown, 5-28 × 4-20 × 1-5 mm, hilum 1-2 × 1 mm, elliptic. Fig. 5 .

Distribution.

China (Anhui, Fujian, Guizhou, Guangdong, Guangxi, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Zhejiang); Japan (Honshu, Kyushu, Shikoku); Laos; South Korea (North Gyeongsang, South Gyeongsang, North Jeolla, South Jeolla); Thailand; Vietnam.

Etymology.

Wisteria - opsis = like (Gk), resembling the genus Wisteria .

Figures

Figure 5. Wisteriopsis japonica (Siebold & Zucc.) J. Compton & Schrire. A Habit B stipels C lower surface of leaflet D flower bud with bract and bracteoles E flower F 1 calyx outer surface F 2 calyx inner surface and detail of hairs G standard petal inner surface H wing petal I keel petal J staminal column K ovary and style L pods M pod interior and seed N ventral view of seed O lateral view of seed A-C, E-K from Maximowicz s. n .. 1863 D from Oldham 386, L-O from Togasi MSM 1, 1950. Drawn by Margaret Tebbs.