SYNOPSIS OF BEGONIA (BEGONIACEAE) FROM THE NORTHERN ARM OF SULAWESI AND SANGIHE ISLAND, INDONESIA, INCLUDING THREE NEW SPECIES Author Ardi, W. H. Research Center for Biosystematics and Evolution, National Research and Innovation Agency (BRIN), Jalan Raya Jakarta-Bogor Km 46, Cibinong, Kabupaten Bogor, Jawa Barat 16911, Indonesia. E-mail: wisn 005 @ brin. go. id. wisn005@brin.go.id Author Thomas, D. C. Research and Conservation, Singapore Botanic Gardens, National Parks Board, 1 Cluny Road, Singapore 259569. text Edinburgh Journal of Botany 2022 2022-08-18 79 405 1 50 http://dx.doi.org/10.24823/ejb.2022.405 journal article 10.24823/EJB.2022.405 1747-0036 Key to the Begonia species of the northern arm of Sulawesi and the Sangihe Talaud Islands 1a. Plants rhizomatous, creeping or decumbent ________________________________________ 2 1b. Plants erect _______________________________________________________________________ 6 2a. Plants rhizomatous ______________________________________________ 13. B. mendumiae 2b. Plants creeping or decumbent, not rhizomatous ____________________________________ 3 3a. Petioles 0.5–2 cm long _____________________________________________ 17. B. sidolensis 3b. Petioles 3–16 cm long ____________________________________________________________ 4 4a. Adaxial leaf lamina with sparse indumentum of bristly hairs between the veins; female flower 2-tepalled ______________________________________________________ 20. B. willemii 4b. Adaxial leaf lamina glabrous; female flowers 5-tepalled _____________________________ 5 5a. Petioles moderately hairy with white hairs; veins hairy on the abaxial leaf lamina surface; male flowers with 19–21 stamens ____________________________ 3. B. carnosa 5b. Petioles glabrous except for very sparse indumentum on the joint of the petiole and lamina; abaxial surface of leaf lamina glabrous; male flowers with 75–77 stamens 7. B. gemella 6a. Male and female flowers occurring together in bisexual inflorescences and open at the same time ________________________________________________________________________ 7 6b. Female inflorescences or solitary flowers separated from the male inflorescences by at least one internode, protogynous _________________________________________________ 10 7a. Male flowers with four tepals, anther connectives projecting at the apex ____________ 8 7b. Male flowers with two tepals, anther connectives not projecting at the apex 15. B. rieckei 8a. Female flowers or fruit with persistent bracteoles; fruit dehiscent, a dry capsule, fruit wings well developed and unequal _________________________________________________ 9 8b. Female flowers or fruit without persistent bracteoles; fruit indehiscent, fleshy, fruit wings poorly developed or sometimes wingless __________________________ 1. B. aptera 9a. Plant hairy, leaf lamina ovate, apex acuminate __________________________ 22. B. hirtella 9b. Plant glabrous, leaf lamina broadly ovate to suborbicular, leaf lamina apex rounded 21. B. cucullata 10a. Leaves elliptic, venation pinnate __________________________________________________ 11 10b. Leaves ovate to elliptic or broadly ovate, venation palmate-pinnate _________________ 14 11a. Female inflorescence peduncle < 1 cm long; female flower pedicels 3–7 mm long __ 12 11b. Female inflorescence peduncle> 1 cm and up to 2 cm long; female flower pedicels 8–12 mm long ____________________________________________________ 8. B. hispidissima 12a. Leaf lamina length-to-width ratio> 3:1, glabrous or sparsely hairy with bristly hairs between the veins, abaxially hairy on the veins only; female flower pedicel 3–4 mm long; ovary glabrous to glabrescent _______________________________________________ 13 12b. Leaf lamina length-to-width ratio <3:1, densely hairy on both surfaces, hairs sometimes branched; female flower pedicel c. 7 mm long; ovary densely hairy 12. B. masarangensis 13a. Leaf lamina margin serrate or double serrate to shallowly lobed, leaf lamina adaxially with distinctly sunken primary and secondary veins; male flower tepals 5–6 × 6–7 mm , stamens 21–25 ___________________________________________________ 16. B. rolandfadlii 13b. Leaf lamina margin entire to serrulate in the distal third of the lamina, veins on adaxial lamina surface not sunken; the male flowers with larger tepals (10–13 × 10–11 mm ) and more stamens (c.40) ___________________________________________ 5. B. cuneatifolia 14a. Male inflorescences not subumbellate, showing dichasial or monochasial branching with at least the basal internodes> 1 mm long ____________________________________ 15 14b. Male inflorescences subumbellate, i.e. consisting of strongly condensed cymes with internodes < 1 mm long __________________________________________ 2. B. capituliformis 15a. Female flowers with 5 tepals _____________________________________________________ 16 15b. Female flowers with 4 tepals _____________________________________ 4. B. chiasmogyna 16a. Stem hairy _______________________________________________________________________ 17 16b. Stem glabrous ___________________________________________________________________ 20 17a. Stem densely hairy with bristle or pilose hairs (> 0.5 mm long); male inflorescence a thyrse with monochasially or dichasially branching partial inflorescences; male flower tepals 5–11.5 × 6–12 mm ________________________________________________________ 18 17b. Stem sparsely hairy with short bristle hairs (< 0.5 mm ); male inflorescence a compound thyrse with multiple lateral branches, each with multiple cymose partial inflorescences; male flower tepals minute (4–5 × 4–5 mm ), broadly ovate to suborbicular _______________________________________________________ 18. B. sojolensis 18a. Plant covered with white hairs; male flower tepal margin entire, not ciliate; female flower tepals ovate; ovary glabrous _______________________________________________ 19 18b. Plant covered with crimson hairs; male flower tepal margin ciliate; female flower tepals obovate; ovary hairy _______________________________________________ 6. B. gambutensis 19a. Male inflorescence a thyrse composed of up to 4 lateral cymose partial inflorescences, each monochasially branching; female inflorescence or infructescence with short peduncle ( 1–2 mm long) ___________________________________________ 14. B. pitopangii 19b. Male inflorescence a thyrse composed of up to 6 lateral cymose partial inflorescences, each dichasially branching; female inflorescence with longer peduncle ( 5–10 mm long) 19. B. strachwitzii 20a. Infructescence peduncle 10–20 mm long ________________________ 11. B. macintyreana 20b. Infructescence peduncle < 5 mm long ____________________________________________ 21 21a. Fruit pendulous on thin pedicel, fruit wings cuneate at base and truncate or subtruncate at the apex; seed-bearing part cylindrical ___________________ 10. B. kinhoi 21b. Fruit pedicel deflexed, fruit wings rounded at base and truncate at the apex; seed-bearing part ellipsoid __________________________________________ 9. B. insularum