Begonia ozotothrix D.C.Thomas

Thomas, Daniel C. & Ardi, Wisnu H., 2020, Synopsis of Begonia (Begoniaceae) of southwest Sulawesi and the Selayar Islands, Indonesia, including one new species, Phytotaxa 437 (2), pp. 73-96 : 86-88

9. Begonia ozotothrix D.C.Thomas in Thomas et al. (2009: 105) ( Fig. 1 & 5 )

Sect. Petermannia

Type:— INDONESIA. Sulawesi, Central Sulawesi: Gunung Katopas, 7 May 2008, D.C. Thomas & W.H. Ardi 08-67 (holo E[00502339]!, iso BO!, CEB!).

Additional literature:— Thomas et al. (2011: 252) [identification key]; Hughes et al. (2018: 227) [photo plate]; Ardi et al. (2018: 43) [photo plate, distribution map].

Description:— Perennial, erect, monoecious herb to ca. 75 cm tall; with microscopic simple trichomes on all vegetative parts and multicellular, simple and branched trichomes up to 3 mm long on the stem, petioles and veins of the abaxial leaf lamina. Stem branched; internodes 2‒7.9 cm long, densely hairy to glabrescent. Leaves alternate; stipules caducous, ca. 15‒32 × 6‒20 mm, oblong to elliptic, with an abaxially prominent midrib, apex narrowed into bristle up to 2 mm long, abaxially hairy to glabrescent; petioles 4.1–18.6 cm long, hairy; lamina basifixed, 11–24.8 × 6.4–15.3 cm, elliptic, asymmetric, base cordate with not or slightly overlapping lobes, apex acuminate, margin dentate and denticulate between the larger teeth or serrate to biserrate, teeth bristle-pointed, adaxial surface green to dark green, hairy to glabrescent, abaxial surface pale green to reddish, hairy to glabrescent; venation palmate-pinnate, primary veins 6–8, actinodromous, secondary veins craspedodromous. Inflorescences: protogynous; female inflorescences basal to male inflorescence part or solitary, 2-flowered, peduncles 1‒5 mm long, hairy to glabrescent; male inflorescences paniculate-cymose, composed of 1‒5 subumbellate partial inflorescences (internodes of partial inflorescences usually strongly compressed; sometimes basal internodes shortly developed and distal internodes strongly compressed), each with up to 10 flowers, peduncle of male partial inflorescence 2−25 mm long, hairy, bracts caducous, 3‒10 × 2‒6 mm, elliptic, abaxially hairy. Male flowers: pedicels 2–15 mm long, hairy; tepals 2, white or pink, 8–11 × 7.5–12 mm, broadly ovate to suborbicular, base cordate, apex rounded, abaxially sparsely hairy to glabrescent; androecium of ca. 25‒35 stamens, yellow, filaments up to ca. 1.6 mm long, slightly fused at the very base, anthers up to ca. 1.4 mm long, obovate, dehiscing through unilaterally positioned slits that are ca. ½ as long as the anthers. Female flowers: pedicels 1−4 mm long, hairy; tepals 5, white or pale pink, unequal to subequal, larger 9–21 × 7–12 mm, ovate to elliptic, smallest one 8−12 × 3−8 mm, obovate or narrowly elliptic, outer surface hairy; ovary 12–21 × 3.5–5 mm (excluding the wings), cylindric, wings 3, equal, base rounded to cuneate, apex truncate, widest point up to 7.5 mm (apically), hairy, locules 3, placentation axile, placentae bilamellate; style basally fused, 3–branched, each stylodium bifurcate in the stigmatic region, stigmatic surface a spirally twisted papillose band, stylodia yellow, stigma orange. Fruit: dry capsule; peduncles 3.5−5 mm long; pedicels 1–4 mm long, hairy; seed-bearing part 15−22 × 4−6 mm (excluding the wings), cylindric, wing shape as for ovary, hairy to glabrescent. Seeds barrel-shaped, ca. 0.3 mm long.

Distribution:— Indonesia, endemic to Sulawesi: Central Sulawesi (Mt. Katopas and Mt. Lumut), South Sulawesi ( Enrekang District, Soppeng, Bantimurung National Park), and Southeast Sulawesi (Sikori village, Bombana District) ( Fig. 1B ).

Habitat:— Forest floor, the base of limestone boulders, and wet rock walls or limestone cliffs in lowland to upland primary to strongly disturbed rainforest at 0–800 m elevation.

Notes:— This species was originally described from a few collections from Central Sulawesi ( Thomas et al. 2009b), but is now known to be relatively widespread on Sulawesi ( Thomas et al. 2011, Ardi et al. 2018; see Fig. 1B ).

Provisional IUCN conservation assessment:— Least Concern (LC) (Ardi et al. 2018).

Additional specimens examined:— INDONESIA. Sulawesi, Central Sulawesi: rec. Menado, Sub div. Poso, P.J. Eyma 3517 ( BO, K, L, SING, U) ; Tojo Una-una District, Bulan Jaya village , 21 Apr. 2008, D.C. Thomas & W.H. Ardi 08-52 ( BO, CEB, E) ; Bulan Jaya village , 21 Apr. 2008, D.C. Thomas & W.H. Ardi 08-53 ( BO, CEB, E) ; between the villages of Bulan Jaya and Linkasa , 21 Apr. 2008, D.C. Thomas & W.H. Ardi 08-56 ( BO, CEB, E) ; close to Uwetangko village , 322 m, 22 Apr. 2008, D.C. Thomas & W.H. Ardi 08-58 ( BO, CEB, E) ; Watusongo Village, Mt. Katopas , 11 May 2008, D.C. Thomas & W.H. Ardi 08-72 ( BO, CEB, E) ; Watusongo Village, Mt. Katopas , 11 May 2008, D.C. Thomas & W.H. Ardi 08-74 ( BO, CEB, E) . South Sulawesi: Bantimoeroeng , 25 June 1937, C.G.G. J. van Steenis 10443 ( BO) ; Bantimoerong and vicinity. 20 Feb. 1938, P. Buwalda 3701 (K) ; Bantimoerong and vicinity, 20 Feb. 1938, P.J. Eyma 3701 (E, K, L, U) ; Maros, Tompokbalang , 27 Sep. 1975, S. Soenarko 304 ( BO, K) ; Southwest Peninsula, NE of Makassar within 54-60 km on the road, Karaenta Forest Reserve , 7 July 1976, W. Meijer 10965 ( BO, L) ; Maros, Bantimurung Park, South Slope , 11 June 1986, S.C. Chin 3445 (K) ; Karaenta Forest Reserve , 15 Apr. 2009, D.C. Thomas & W.H. Ardi 09-76 ( BO, E, L) ; Enrekang Botanical Gardens (wild population), 11 Nov. 2018, W.H. Ardi 357 ( BO, KRB, SING) ; Maroanging , Enrekang, 11 Nov. 2018, W.H. Ardi 358 ( BO, KRB, SING) ; Soppeng , 12 Nov. 2018, W.H. Ardi 360 ( BO, KRB, SING) ; Eremerasa village , 23 Nov. 2018, W.H. Ardi 372 ( BO, KRB, SING) ; Permandian Eremerasa , 23 Nov. 2018, W.H. Ardi 373 ( BO, KRB, SING) . Southeast Sulawesi: Bombana Regency, Rakadua, Sikori village , 28 Feb. 2017, W.H. Ardi 188 ( BO; KRB; SING) ; Bombana Regency, Rakadua, Sikori Village , 28 Feb. 2017, W.H. Ardi 189 ( BO; KRB; SING). Cultivated material: Enrekang Botanic Gardens , 30 May 2018, W.H. Ardi 195 ( KRB) ; Enrekang Botanic Gardens , 10 Nov. 2018, W.H. Ardi 355 ( BO, KRB, SING) .

Figures

FIGURE 1. Distribution maps of Begonia species occurring on the southwestern arm of Sulawesi or the Selayar Islands (georeferenced specimen data from major collections [B, BO, E, K, KRB, L, SING], the Begonia Resource Center [Hughes et al. 2015a], as well as some additional confirmed observations). Grey lines indicate 1° graticules.

FIGURE 5. Begonia ozotothrix. A: Growth habit. B: Stipule, scale bar = 12 mm. C: Branched trichomes on petiole; scale bar = 2 mm. D: Inflorescence, female partial inflorescence basal, male partial inflorescences in distal part; scale bar = 4 cm. E: Female partial inflorescence, female flowers in side view; scale bar = 2 cm. F: Female flower, front view, scale bar = 10 mm. G: Male flower, front view; scale bar = 10 mm. H: Ovary cross-section, bilamellate placentation, scale bar = 2 mm. I: Fruit, side view; scale bar = 10 mm. A-B, D-I: Thomas & Ardi 09-76. Photos: D.C. Thomas.