Begonia doloisii Rimi, 2015

Repin, Rimi, Sang, Julia, Kiew, Ruth & Mujih, Handry, 2015, Eleven new species of Begonia (Begoniaceae) from the Crocker Range, Sabah, Malaysia, Phytotaxa 208 (1), pp. 1-20 : 9-10

5. Begonia doloisii Rimi , sp. nov. ( Figure 6 )

Sect. Baryandra

Begonia doloisii Rimi similar to B. diwolii in its creeping habit but the species is distinct from B. diwolii in its smaller stipules to 8 × 3.5 mm with a serrate margin (not 9–19 × 3.5–8 mm and with an entire margin as in B. diwolii ), its smaller ovate leaves 3–4.5 × 3–3.5 cm with an acuminate apex and doubly serrate margin (not orbicular to reniform, to 6.5 × 6.5 cm, with a rounded apex and entire margin), inflorescences with ca. 6 pairs of persistent bracts, the lower four spaced along the rachis and the upper two congested below the flowers (not with a single pair of caducous bracts) and smaller capsule ca. 6 mm long with narrower wings ca. 1.5–2 mm wide (not with capsules 10–13 mm long with wings 4–5 mm wide).

Type:— MALAYSIA. Borneo. Sabah. Penampang District: Crocker Range Park, Inobang Substation , on slope nearby trail before permanent research plot, 2010, Dolois S. SNP 36823 (holotype SNP!; isotypes SAN!, KEP!) .

Low herb. Stem creeping and rooting at the nodes, 20–28.5 cm long, slender, ca. 1.5–2 mm thick, deep purplered, with sparsely appressed pubescence; internodes 1.5–3.5 cm long; branches short, erect, 10–20 cm long. Stipules broadly lanceolate, 6–14 × 2.2–11 mm, margin serrate, teeth tipped by a long hair, keeled on the midrib lower surface, persistent. Leaves alternate, distant, oblique or not; petiole purple, lowermost longest, 1.4–5 cm long, pubescent, hairs ca. 0.75 mm long; lamina upper surface plain whitish green with dark red veins, held horizontally, glossy with scattered stubby dark red hairs, drying parchment-like, ovate, slightly asymmetric, 3–6.5 × 3–5.4 cm, broader side 1.3–2.8 cm, base cordate sometimes deeply so, larger basal lobe 0.3–0.6 cm long, margin deeply doubly serrate, teeth 2–5 mm long tipped by a long hair ca. 0.75 mm long, apex acuminate, acumen 0.5–2 cm long; venation palmate-pinnate with 2 pairs of veins at the base of the midrib that branch once or twice before reaching the margin and 2 veins along each side of the midrib with 1 vein in the larger basal lobe, impressed above, prominent and with short appressed hairs beneath. Inflorescences protandrus from the uppermost leaf axils, erect, rachis reddish 4.5–5 cm long, peduncle 1.3–3 cm long, lateral branches few and short, male flowers basal and the female distal. Bracts persistent, lower ones ca. 4 pairs spaced along the rachis, broadly elliptic, 7–12 × 2.5–8 mm, apex acute, pale red or pale green tinged red, bracteoles congested below flowers, bright rosy red, boat-shaped and encircling the rachis, positioned horizontally, 6–6.5 × 2.5–5 mm, margin toothed only in the upper half; upper bracteoles ca. 1 × 0.5 cm, broadly oval. Female flowers more-or-less sessile, ovary 3-winged, 3-loculate, each locule with 2 placentas; tepals 5, outer 3 broadly ovate, 2–7 × 3–3.5 mm, apex apiculate, inner 2 broadly lanceolate, 2–7 × 1.5–3 mm, styles 3, pale yellow, 2–4 mm long, divided to base, Y-shaped; stigma pale yellow, papillose forming a continuous twisted band. Male flowers with pedicel 5–11 mm long, tepals 4, pale pink, glabrous, entire, outer pair broadly elliptic, 6–9 × 4–5.5 mm, tinged deep red towards the rounded apex, inner pair narrowly obovate, 4–9 × 1.5–3 mm; stamens subglobose, ca. 30, joined in a torus ca. 1.5 mm long, filaments 0.5–0.8 mm long, anthers pale orange, obovate or oblong, 0.5–0.6 mm long, apex emarginate. Capsule with pedicel ca. 3.5 mm long, capsule ca. 6 × 7 mm between wings, wings almost equal with two ca. 1.5 mm wide and the third ca. 2 mm wide, rounded distally, narrowed to base, dehiscing between wing and locule. Seed barrel-shaped, ca. 0.5 × 0.25 mm, columnar cells more than half the length of seed.

Distribution:— MALAYSIA. Borneo. Endemic in Sabah.

Habitat:—In primary lowland rain forest, on a steep loamy bank, at 775 m elevation.

Etymology:—Named in honour of Dolois Sumbin, senior research assistant of the SNP Herbarium and specialist in tree identification, who found and collected this begonia.

Additional specimens examined: — MALAYSIA. Borneo. Sabah. Penampang District: Crocker Range Park – sub-station Inobong , Roselen RS 020 ( SNP), specimen cultivated at Kipandi Park from specimens collected from Kalabakan, Julia & Kiew KNP 36812 ( SNP) ; Kalabakan District – Sapulut , Nurod Uroi FR, Duni et al. SNP 20848 ( SNP) ; Crocker Range – Sinsuran Road, Mile 23/24, Dransfield JD 5537 ( K, L, SAN), Salt Trail 5 o 30.13’N 116 o 05.19’E, Sept 2012, Lens et al . PH 115 ( SNP, KEP) .

Notes:—Among Bornean begonias, deeply toothed leaves are unusual and laciniate leaves unknown. Its deeply toothed margin plus its creeping habit and small round leaves with red veins combine to make this a decorative species.

In being protandrous and having inflorescences with boat-shaped bracteoles and female flowers with a 3-locular ovary with bilamellate placentas it belongs to sect. Baryandra. The great diversity of sect. Baryandra is centred in the Philippines ( Rubite et al., 2013) with until now only three species, B. diwolii , B. gueritziana and B. subnummularifolia Merrill (1926: 403) , recorded from Borneo and all of these endemic to Sabah.

Figures

FIGURE 6. Begonia doloisii. A & B. Habit; C. Male flowers with 2+2 tepals; D. Unopened female flower and opened male flower. All photos from KNP 36812 by Julia Sang.