Begonia patar Randi, 2022

Randi, Agusti, Ardi, Wisnu H., Girmansyah, Deden, Sitepu, Bina Swasta & Hughes, Mark, 2022, Three new species, one new record and an updated checklist of Begonia (Begoniaceae) from Kalimantan, Indonesia, Phytotaxa 533 (1), pp. 62-72 : 65-67

Begonia patar Randi , sp. nov. B. sect. Petermannia ( Fig. 2 ).

Type: — INDONESIA, West Kalimantan Province, Sintang Regency, Kelam Permai District, Ensaid Panjang Village , Bukit Rentab , 0°8’7.72”N, 111°43'56.65"E, 55 m elev., 19 October 2020, A . Randi AR-1051 (holotype BO!; isotype WAN!) .

Diagnosis:— It is allied to B. kiamfeei Kiew & S.Julia (2007: 215) in having a creeping habit and hairy leaves, but differs in having larger (8–16 × 6–12 cm vs. 6.5–8.5 × 5–8.5 cm) variegated (vs. uniform green) leaves, and pistillate flowers in pairs (vs. single) per node.

A short creeping herb. Stem stout, unbranched, 5–26 cm long, 4–8 mm in diameter, zig-zag, covered with villous hairs, succulent, pink to crimson; nodes with conspicuous leaf and stipule scars, internodes 4–19 mm apart. Stipules persistent, asymmetric, broadly ovate to broadly elliptic, 5–10 × 4–8 mm, with conspicuous hairs on main rib abaxially, glabrous adaxially, margin entire, apex acute to obtuse to retuse, erect then becoming recurved with aging, greenish-yellow when fresh, usually pinkish at base. Leaves simple, alternate, oblique; petiole to 12 cm long, 1.5–3 mm in diameter, with villous or pilose hairs, pink to brownish red; lamina ovate, 8–16 × 6–12 cm (basal lobes included), strongly asymmetric with overlap basal lobes, margins dentate when young then becoming crenate by age and undulated, often with thin red margin, apex obtuse, acute to caudate; adaxial surface variegated, dark green to purplish-brown with cream to light green on venations, completely covered by pilose hairs coloured white or pink to brownish red, abaxial surface very striking with a combination of pink to red with cream to light green on venations, with sparse and scattered pilose hairs; venation palmate-pinnate, midrib distinguishable, with 2–4 lateral veins each side, other primary veins branching dichotomously; young leaves brownish-red, completely covered by dense hairs adaxially and looser with age. Inflorescence protogynous, terminal then becoming opposite of leaves with aging, erect, up to 27 cm long, 2–4 mm diameter at the base, with sparse pilose hairs, roughly zig-zag for whole length, cream-pink to dark red; pistillate flowers placed ⅓ – ⅔ of inflorescence length from the base, to 4 flowers, a pair for each node, rarely solitary, to 5 cm apart, peduncle to 4.5 cm long; upper distal to 12 cm long, peduncle 1.5–3 cm long, cyme branching to 2 orders, pinkish to red; bracteoles caducous, broadly ovate, 3–6 × 3–5 mm, margin entire, apex acute to obtuse to retuse, white or sometimes slightly pinkish, symmetric. Staminate flower with 4 tepals, 2 outer and 2 inner, glabrous; pedicel slender, 5–8 mm long, 0.5–1 mm diameter, glabrous; outer tepals broadly ovate to orbicular, 5.5–8 × 6–7 mm, margin entire, apex rounded, white; inner tepals smaller than outer ones, elliptic to oblanceolate, 3.9–4.2 × 1.8–2.2 mm, margin entire, apex acute to rounded, white; androecium symmetric, 3–4 mm long, with 38–40 yellow stamens, filament 0.2–1 mm long, anthers obovate, 0.8–1.2 × 0.5–0.8 mm, with divided apex, opened by slit. Pistillate flower at anthesis phase 13–20 mm across; pedicel ca. 10 mm long, ca. 1 mm diameter, white to pale pink, glabrous; ovary 3-locular, asymmetric or sometimes symmetric, 7–9 × 12–14 mm (wings included), white, pale pink to pale purple; tepals 5, glabrous, 2 outer and 3 inner; outer tepals broadly ovate to orbicular, 6.5–7 × 7 mm, margin entire, apex broadly acute to rounded, white or sometimes pinkish at base; inner tepals with 2 broader and 1 smaller, broader ones broadly elliptic to suborbicular, 6–7.5 × 5–6.5 mm, apex broadly acute to rounded, white or sometimes pinkish at base, smaller one elliptic or obovate, ca. 5.5 × 3 mm, apex acute to obtuse to rounded, white; styles 3, ca. 3 mm long, bifid, pale to golden yellow; stigmas anchor-shaped, forming a short papillose spiral band. Fruit nodding, 6–15 × 8–18 mm (wings included), green to pink with dark red wings, glabrous; wings 3, subequal, often curved sideways, apex rounded, 3–6 mm wide at the widest point.

Ecology:— Creeping on vertical granite rocks at 50–100 m elev. This species grows directly on the surface of granite rocks or on the surface of thin mosses with medium light intensity.

Distribution:— Endemic to Borneo, so far it has only been found in Bukit Rentab, Ensaid Panjang Village, Sintang Regency, West Kalimantan.

Etymology: —The epithet of this species is derived from the local name patar , which means patterned from the Dayak Desa language, referring to the colour variation of the leaves.

Provisional Conservation Status:— Critically endangered (CR) B1ab(iii) + B2ab(iii) ( IUCN, 2019). This species is found on a single small hill and is limited to rocky cliffs at the foot of the hill on the south side. Three subpopulations were found in the area with an EOO of 0.01 km ² and AOO of 4 km ² only. The habitat of the population is very easy to reach, and the distribution area is also a tourist location that is free to be entered by anyone. Although the habitat is a protected forest, forest fires have occurred several times in this location and shifting cultivation activities of local communities are still very active in the area. The population could also be threatened due to collection by plant hunters for use as ornamental plants. These threats can push this species towards possible extinction in a short time if there is no conservation effort. Therefore, ex-situ conservation of this species is urgently needed.

Uses:— The Dayak Desa people who live in the longhouse of Ensaid Panjang Sintang use it as a mixture of traditional ingredients to protect women after childbirth and their babies from demonic disturbances, besides that it is also used as a traditional herb to treat headaches.

Notes:— Begonia patar has a stout stem, 5–26 cm long and short internodes 0.4–1.9 cm apart, in contrast to B. kiamfeei which has a much more slender stem up to 50 cm long and internodes 2.5–4.5 cm long. The leaves of B. patar are distinctly variegated with a combination of dark green to purplish-brown with cream to light green on the venation adaxially and pink to red with cream to light green on the venation abaxially, while B. kiamfeei leaves are mid-green with pale green veins adaxially and paler beneath. The pistillate flowers of B. patar are in groups of up to 4 flowers, in a pair for each node, inner tepals 3 with 2 large and one smaller tepal in between, while B. kiamfeei bears up to 6 flowers which are solitary at each node, inner tepals 3 of the same size and shape. The habitat of the two species is also different, as B. patar grows on granite rocks, while B. kiamfeei grows on limestone.

The habit, and attractive variegated ovate leaves of B. patar are also superficially similar to B. conipila Irmsch. ex Kiew (2001a: 287) , however it has pale veins on a dark background, whereas B. conipila has dark veins on a pale background. In addition, some key characters are distinctive like the stipules broadly ovate to broadly elliptic in B. patar , while lanceolate in B. conipila . The petiole of B. patar is much longer (up to 12 cm long vs. to 5 cm) compared with B. conipila . Inflorescence in B. patar is terminal then becoming opposite to the leaves with ageing, up to 27 cm long, with two pairs of pistillate flowers at ⅓ – ⅔ of inflorescence length from the base, whereas B. conipila has axillary inflorescences, up to 9.5 cm long, with a single basal pistillate flower. The number of stamens is 38–40 in B. patar , and 10–11 in B. conipila . Their habitats are also very different, as B. patar grows on vertical granite rocks to 100 m elev., and B. conipila grows on limestone to ca. 1170 m elev.

Figures

FIGURE 2. Begonia patar Randi. A. Plant habit in-situ; B. Stipules and the base of petioles; C, D. Adaxial and abaxial surfaces of leaf; E. Pilose hairs on adaxial surface; F. Inflorescence; G. Top view of staminate flower; H. Side view of staminate flower; I. Top view of pistillate flower; J. Side view of pistillate flower; K. Mature fruits; L. Cross sections of fruit. Scale bars: B: 5 mm, C–D: 3 cm, E: 10 mm, F–H: 5 mm, I: 10 mm, J: 5 mm, K–L: 10 mm. All photos by A. Randi AR-1051.