Capparis macrantha Souvannakhoummane, Fici & Lanorsavanh, 2020

Souvannakhoummane, Keooudone, Fici, Silvio, Lanorsavanh, Soulivanh, Park, Jeong Ho, Kang, Ho Sang & Bounithiphonh, Chaloun, 2020, Capparis macrantha sp. nov. (Capparaceae, Brassicales), a new shrub species from a deciduous forest of the Nam Kading National Protected Area (central Lao PDR), European Journal of Taxonomy 656 (656), pp. 1-12 : 3-9

Capparis macrantha Souvannakhoummane, Fici & Lanorsavanh sp. nov. urn:lsid:ipni.org:names:77209673-1

Figs 1–2

Type material

LAO PDR • Bolikhamxai Province, Pakkading district, Nam Kading National Protected Area ; 221 m a.s.l.; 16 May 2019; Lanorsavanh et al. SL1641; holotype: HNL, isotype: FOF .

Diagnosis

A C. radula Gagnep. stipulis rectis brevioribus, foliis majoribus, sepalis petalisque majoribus, staminum numero superiore, filamentis longioribus, gynophoro atque ovario longioribus praecipue differt.

Etymology

The specific epithet is composed of the Greek words ʻmakrósʼ, meaning ʻlargeʼ, and ʻánthosʼ, ʻflowerʼ.

Description

Erect or ascending shrub 1–3 m tall. Branches greyish, bearing small knobs surmounted by a thorn; twigs when young pubescent with simple hairs, later glabrous, at the base usually surrounded by cataphylls. Stipular thorns straight, directed upwards or slightly recurved, ca 2 mm long. Petioles 10–24 mm long, glabrous. Leaf blades coriaceous, lanceolate-elliptic, ca 3.7–4.1 times as long as wide, 30–36× 7.5– 10.5 cm; base obtuse or rounded; apex acute or acuminate, with tip 0.8–1.4 cm long; upper surface dark green, lower surface light green, both ones glabrous; veins ca 8–12 on each side of the midrib, decurrent along the margin; young leaves pubescent, silver to pale green with purple patch near apex. Flowers white, fragrant, serial, 2–4 in supra-axillary rows; pedicels 3.5–4.2 cm long, glabrous, surrounded at base by conferted bracts; bracts triangular, ca 1.8 mm long. Sepals 2–2.5× 0.7–1 cm, greenish, acute at apex, glabrous on both sides, outer pair boat-shaped, inner pair thinner. Petals oblong to obovate, 3.5– 4.5× 1.2–2.6 cm, puberulous outside, white with yellow or purple honey-guide. Stamens ca 100–135; filaments ca 3.5–4.5 cm long; anthers 1.8–2 mm long. Gynophore 3.8–4.2 cm long, glabrous; ovary ellipsoid or oblong, 5–6× 1.7–2 mm, glabrous, shortly beaked with small knob-shaped stigma. Fruit unknown.

Distribution, habitat and phenology

The new species is so far known from a single location in the Nam Kading National Protected Area in Bolikhamxai Province, at 18°11′44.9″ N, 104°26′25.1″ E ( Fig. 3 ). Capparis macrantha sp. nov. has been observed in mixed deciduous forest on limestone, at ca 200–230 m elevation, with Amorphophallus laoticus Hett. , Arisaema Mart. sp., Wurfbainia glabrifolia (Lamxay & M.F.Newman) Škorničk. & A.D.Poulsen. The flowering occurs from May to June.

Taxonomic remarks

Capparis macrantha sp. nov. is mainly distinguished from other species of sect. Monostichocalyx by its large flowers in supra-axillary rows, as well as by its large leaves, high number of stamens and elongate ovary. Among the species of the genus with serial flowers, C. macrantha sp. nov. shows some affinities with C. radula , recorded in Thailand, Lao PDR, Cambodia and Vietnam, which however differs in the longer, recurved stipular thorns 3–4 mm long, smaller leaves ca 4.5–9.5× 2.5–6.5 cm, smaller flowers with sepals ca 9–11× 3–5 mm and petals ca 11–14× 6 mm, lower number of stamens (ca 30–40) with filaments 1.75–2 cm long, shorter gynophore 1.6–2.3 cm long and shorter, ovoid ovary ca 2.5–3 mm long ( Jacobs 1965) ( Table 1 ). The new species is also related to C. olacifolia Hook. f. & Thomson, widespread from India and Nepal eastwards to Myanmar, which is distinguished by the smaller leaves 8–13(–16)×(3.5–) 4–6 cm, smaller flowers with sepals 8–10×(3–)4–5(–6) mm and petals (15–)17– 22×ca 5 mm, lower number of stamens (34–38) and densely tomentose ovary 1–1.5 mm wide ( Table 1 ). Various other species recorded from Lao PDR and included by Jacobs (1965) in the Seriales-Group, as C. acutifolia Sweet , C. echinocarpa Pierre ex Gagnep. , C. micracantha DC., C. pyrifolia Lam. , C. tenera Dalzell , C. urophylla F.Chun and C. zeylanica L., are readily distinguished by their small to medium sized flowers, with sepals 3–15 mm long, and by the ovary up to ca 3 mm long ( Table 1 ).

Conservation status

Capparis macrantha sp. nov. is known from the type locality only, occurring in a National Protected Area, where about 10 individuals were observed. Based on our observations, the population is not under immediate threat; however, given the very small area of occupancy known, the new species is assessed here as Vulnerable (VU D1) according to IUCN Red List Categories and Criteria ( IUCN 2012).

Figures

Fig. 1. Capparis macrantha Souvannakhoummane, Fici & Lanorsavanh sp. nov. A. Flowering branch. B. Flower (lateral view). C. Flower (front view). D. Stipular thorn and petiole. E. Sepals. F. Petals. G. Gynophore and ovary. H. Stamens. Drawn from holotype (Lanorsavanh et al. SL1641) by K. Souvannakhoummane.

Fig. 2. Capparis macrantha Souvannakhoummane, Fici & Lanorsavanh sp. nov. A. Habit and detail of a branch bearing thorns. B. Flowering branch. C. Young twigs. D. Young leaves. E. Flower (top view). F. Flower (lateral view). G. Petal (outside view). Photos by S. Lanorsavanh.

Fig. 3. Known distribution of Capparis macrantha Souvannakhoummane, Fici & Lanorsavanh sp. nov. (red circle).