Begonia johntania Ardi & D.C.Thomas, 2018

6. Begonia johntania Ardi & D.C.Thomas , spec. nov. ( Figures 1 View FIGURE 1 & 7 View FIGURE 7 )

Sect. Petermannia

Begonia johntania is similar in habit and leaf shape to B. capituliformis Irmscher (1913: 354) View in CoL , but differs in having longer petioles ( 3–12 cm vs 3–5 cm), denticulate leaf margins (vs broadly dentate), adaxially glabrous leaves (vs sparsely bristly between or on the veins), paniculate-cymose male inflorescences (vs capituliform) and fruits on hanging, 2–2.8 cm long pedicels (vs fruit not pendulous, pedicels 5–8 mm long).

Type:— INDONESIA. Sulawesi, Southeast Sulawesi, North Konawe, Linomoyo transmigration village, 16 February 2017, W.H. Ardi WI 163 ( holotype BO!; isotypes KRB!, SING!) .

Perennial, monoecious herb, erect or appressed to substrate at the base and distally erect, to ca. 50 cm tall. Stem branched; internodes 3–12 cm long, brownish-reddish, covered with dense indumentum of bristly hairs up to ca. 1.5 mm long. Leaves alternate; stipules caducous, 8–15 × 4–6.5 mm, ovate to oblong, with an abaxially slightly prominent midrib, apex narrowed into bristle projecting up to 3 mm, concolourous with the stem, translucent at the margin, abaxially hairy; petioles 6–13 cm long, adaxially shallowly channelled, concolourous with the stem, hairy; lamina 10– 18 × 6–10 cm, asymmetric, ovate to elliptic, base cordate and lobes not or just slightly overlapping, apex acuminate, margin denticulate, adaxial surface green, with red veins, glabrous, abaxial pale green, hairy; venation palmate-pinnate, primary veins 6–7, actinodromous, secondary veins craspedodromous. Inflorescences protogynous, internodes between female and male partial inflorescence strongly compressed; female inflorescences 2-flowered, peduncles ca. 1 mm long; male inflorescences compressed paniculate-cymose with 3 − 5 monochasial partial inflorescences, each with up to 7 flowers, bracts caduceus, not observed. Male flowers: pedicels 14–18 mm long, reddish, hairy; tepals 2, white, 6–9 × 5–7 mm, ovate, base slightly cordate, apex rounded, outer surface hairy with red trichomes; androecium of ca. 30–32 stamens, yellow, filaments up to ca. 0.5 mm long, slightly fused at the very base, anthers up to ca. 1 mm long, oblong to narrowly obovate, dehiscing through unilaterally positioned slits that are ca. ½ as long as the anthers. Female flowers: pedicels 1.5–2.5 cm long, reddish, hairy; tepals 5, white tinged pink, unequal, one smaller 6–7 × 3–4 mm, the four larger 8–10 × 5–6 mm, ovate to elliptic, outer surface hairy; ovary (excluding wings) 11–13 × 4–4.5 mm, ellipsoid, pale green, hairy with red trichomes, locules 3, placentation axile, placentae bilamellate, wings 3, equal, pale green, base rounded to cuneate, apex subtruncate to truncate, up to 7 mm at widest point (apically or subapically); style ca. 3.5 mm long, basally fused, 3–branched, each stylodium bifurcate in the stigmatic region, stigmatic surface a spirally twisted papillose band, orange. Fruits: peduncles ca. 2 mm long; pedicels 2–2.8 cm long, pendulous; seed-bearing part ellipsoid, 13–20 × 4.5–7 mm (excluding the wings), hairy, dehiscent, splitting along the wing attachment, wings shape as for ovary, up to 8 mm at the widest point (apically or subapically). Seeds barrel-shaped, ca. 0.2 mm long.

Distribution:— Indonesia; endemic to Sulawesi, Southeast Sulawesi (known only from the type locality).

Habitat:— Lowland forest, on slopes at the side of a small stream with Cyrtandra spec. , aroids and ferns.

Etymology:— The specific epithet is in honour of Mr. Tan Jiew Hoe, a patron of botanical exploration and plant taxonomy and generous supporter of the Begonia of Sulawesi project.

Notes:— The compressed paniculate-cymose male inflorescence is a rare character among Sulawesi Begonia . Prima facie, this inflorescence looks similar to the inflorescences of Begonia capituliform is from Northern Sulawesi. However, Begonia johntania has less compressed paniculate-cymose inflorescences with short internodes, while B. capituliformis has dense and strongly compressed subumbellate (capitulum-like) male inflorescences. Another difference is the length of the female flower pedicels and fruit pedicels: in B. johntania the fruits are pendulous on up to 2.8 cm long flower and fruit pedicels, while in B. capituliformis the female flower and fruit pedicels are much shorter ( 5–8 mm long) and the flowers and fruits are not pendulous.

Provisional IUCN conservation assessment:— Data Deficient (DD). This species is only known from a single locality; a forest remnant in close proximity to a village. The forests in the wider area are very poorly collected. Consequently, we assess this species as Data Deficient ( IUCN 2012).