Begonia turugsoy Mazo & Rubite, 2022

Mazo, Kean Roe F. & Rubite, Rosario R., 2022, Two new species of Begonia (section Petermannia, Begoniaceae) from the Zamboanga Peninsula, Philippines, and a redescription of Begonia parvilimba, Phytotaxa 538 (2), pp. 163-171 : 166-168

2. Begonia turugsoy Mazo & Rubite , sp. nov. § Petermannia ( Fig. 3 )

Type:— PHILIPPINES. Mindanao, Zamboanga del Norte Province, Municipality of Leon B. Postigo, Brgy. Tinuyop, Molina River, elevation 310 m, 8°3’38.99” N, 122°55’42.37” E, 7 November 2021, K. R. F. Mazo 57 (holotype PNH) .

Monoecious, perennial herb. Stem branched, erect, up to 30 cm tall, 3.0– 4.5 mm in diameter, reddish maroon, sparsely puberulent, internodes (1.6–) 3.8–7.8 cm long, nodes rooting on the lower portion. Stipules caducous, green, oblong, 7–11 × 2–3 mm, glabrous, margin entire, apex caudate. Petioles reddish-brown, terete, 7–23 × 2–4 mm, strigose. Leaves ovate, asymmetric, basifixed, 5.0–7.8 × 2.8–4.0 cm, base obliquely cordate to rounded, margin irregularly serrate, apex acuminate; adaxially surface green, sparsely echinate between veins, veins emergent; abaxially pale green, veins slightly emergent, hirsute on midrib and veins; venation palmate, primary veins 5. Inflorescence terminal, bisexual; panicle 5–8 cm long, peduncle pinkish to dark red, glabrous, 2.0– 2.5 cm long; pistillate flower 1 or 2, arising from the base of inflorescence, staminate flower distal, on short cymes branching up to 3 or 4 times; protogynous. Bracts caducous, puberulent, adaxially reddish maroon, ovate, 5–7 × 2–3 mm, margin entire, apex caudate. Staminate flower pedicel 3–9 mm long, pinkish to red, glabrous; tepals 2, glabrous, white suffused with pink, ovate, 7–9 × 5.0– 5.5 mm, apex rounded; androecium zygomorphic, stamens 15–20, yellow; filaments 0.8–1.0 mm long, fused at base; anthers 1.0– 1.2 mm long, obovoid, apex rounded or retuse. Pistillate flower pedicel 13–23 mm long, reddish maroon or yellowish-green, glabrous; tepals 5, glabrous, white suffused with pink; tepals broadly ovate to suborbicular 12–16 × 5.5–6.8 mm, apex obtuse or rounded; style 3, yellow, apically bifid, 5.4–6.0 mm long, stigma in spiral band and papillose all around. Ovary trigonous-ellipsoid, brownish-red or yellowish-green, 9–14 × 5–8 mm (wings excluded), glabrous, wings 3, subequal, brownish-red or yellowish-green, obtuse distally, 10.4–24.0 × 4.8–11.3 mm; locules 3, placenta bilamellate. Capsule trigonous-elliptic, 14.3–16.0 × 12.6–15.4 mm (wings included), slightly recurved; pedicel 14.5–25.2 mm long; wings 3, subequal, truncate distally, rounded or subcordate proximally, 10.7–25.2 mm long, 5.2–12.6 mm wide.

Phenology:— Observed flowering and fruiting in October and November.

Etymology:— The species is named after the local word “turugsoy” which means standing or upright in Subanen language, reflecting the erect habit of the plant.

Distribution and Habitat:— Begonia turugsoy is endemic to Zamboanga del Norte, Mindanao, where it is currently known only from its type locality. The plant grows on a semi-open area along the river of secondary lowland tropical evergreen forest at 250–310 m elevation.

Notes:— Begonia turugsoy is similar to B. tinuyopensis with ovate leaf shape, terminal inflorescence with twotepaled staminate flowers, and five-tepaled pistillate flowers. However, it differs in habit erect (vs. decumbent); stipule 7–11 × 2–3 mm, caducous, oblong (vs. 5–7 × 2.5–3.0 mm, persistent, ovate to triangular); petioles shorter 7–23 mm (vs. 18–45 mm); bract puberulent (vs. glabrous); pedicels of both staminate and pistillate flowers glabrous (vs. sparse puberulous) and ovary brownish red to yellowish-green, 15–18 × 9.2–11.2 mm (vs. deep pink, 7–10 × 3.0– 1.5 mm).

Proposed Conservation Assessment:— Begonia turugsoy is known only from the type locality with two populations each of about one or three mature individuals. After 16 months of fieldwork with 5 or 6 times/month site visits, no additional populations nor individuals were found. The area is not currently protected under the country’s National Integrated Protected Areas System by the Department of Environment and Natural Resources. Given the ongoing threats such as nearby rubber plantation, forest road construction, small-scale mining illegal logging, and a single area of occurrence, and the small number of <50 mature individuals it is prudent to provisionally assess this species as Critically Endangered CR D.

Figures

FIGURE 3. Begonia turugsoy Mazo & Rubite. A. Habit and habitat; B. Stem; C. Stipule; D. Leaf adaxial surface; E. Leaf abaxial surface; F. Inflorescence showing pistillate flowers; G. Staminate flower, side view; H. Pistillate flower, front view; I. Capsule; J. Inflorescence showing single pistillate flower.All from K.R.F. Mazo 57.