Begonia

Camfield, Rebecca & Hughes, Mark, 2018, A revision and one new species of Begonia L. (Begoniaceae, Cucurbitales) in Northeast India, European Journal of Taxonomy 396, pp. 1-116 : 7-8

Group 2 – Leaves ovate, entire/undulate and asymmetric ( Fig. 2B )

1. Leaves glabrous above (or with very sparse microscopic hairs) ...................................................... 2 – Leaves hairy above ........................................................................................................................... 6

2. Plant with a main stem, up to 120 cm high, leaves not variegated, primary peduncle 2–5 mm ........ ................................................................................................................ B. roxburghii (Miq.) A.DC. – Plant rhizomatous, up to 30 cm high, leaves variegated or not, primary peduncle 5–20 cm .......... 3

3. Leaves broadly ovate, smoothly bullate, styles 2, winged fruit ........................................................ 4 – Leaves narrowly ovate, not bullate, styles 4, wingless fruit ............................................................. 5

4. Lamina variegated with a broad ring, flowers white to pink ........................................... B. rex Putz. – Lamina variegated with markings between main veins, flowers yellow .............. B. xanthina Hook.

5. Leaves usually variegated, outer tepals 1–3 cm long and acute, stamens in a globose cluster, fruit 2 cm long and rhomboid-elliptic ............................................................................. B. burkillii Dunn

– Leaves uniform pale green, outer tepals 2–5 cm long and rounded, stamens in loose rosette, fruit 1 cm long and obpyramidal ................................................................................. B. handelii Irmsch.

6. Leaves variegated ............................................................................................................................. 7 – Leaves not variegated ..................................................................................................................... 10

7. Plant 20–30 cm high, leaves ovate with ring/band markings .......................................................... 8 – Plant <20 cm, leaves ovate-orbicular with spot/dot markings ........................................................ 9

8. Leaf surface bullate, peduncles, flowers and fruit glabrous, anther connective acuminate, wing rounded oblong ................................................................................................................ B. rex Putz.

– Leaf surface with strigose/verrucose, peduncles, flowers and fruit with hairs, anther connective rounded, longest wing crenulated ...................................................................... B. annulata K.Koch

9. Leaves 4–10 cm long, upper leaf surface densely villose, 2–3 flowers, male outer tepals 15–20 mm long, 30–40 stamens, 3 styles ............................................................................ B. scintillans Dunn

– Leaves 10–30 cm long, upper leaf surface sparsely puberulous, 10–20 flowers, male outer tepals 10 –17 mm long, 15–25 stamens, 2 styles ........................................................... B. iridescens Dunn

10. Plants> 40 cm .................................................................................................................................11 – Plants <40 cm ................................................................................................................................ 12

11. Plant covered in long red hairs (5 mm long), peduncles 5–10 cm ....................... B. aborensis Dunn – Plant with sparse short brownish or red pubescence on petioles and under surface of leaf, peduncles 15 –25 cm ...................................................................................... B. silletensis (A.DC.) C.B.Clarke

12. Plant with sparse puberlous hairs, styles 4, fruit wingless ..................... B. tessaricarpa C.B.Clarke – Plant with dense tomentose or villose hairs, styles 2–3, fruit winged ........................................... 13

13. Leaves large, 15–20 cm long, apex acuminate, primary peduncle> 10 cm, fruit with equal wings, 2–6 mm long ................................................................................................. B. obversa C.B.Clarke

– Leaves small, 5–15 cm long, apex acute, primary peduncle <5 cm, fruit with unequal wings, longest wing 12 –30 mm long ........................................................................................ B. thomsonii A.DC.

Figures

Fig. 2. Leaf tracings. A. Group 1: scalloped, lobed or incised leaves. B. Group 2: ovate, asymmetric, and entire leaves.