GULF OF GUINEA CONSERVATION GROUP: Begonias of São Tomé and Príncipe

GULF OF GUINEA ISLANDS' BIODIVERSITY NETWORK

The genus Begonia L. (Begoniaceae) in São Tomé and Príncipe

Vanessa Plana

Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, UK.

Key to Species Description of Species Section Baccabegonia Begonia baccata Begonia crateris Section Squamibegonia Begonia ampla Section Tetraphila Begonia molleri Begonia subalpestris Begonia loranthoides loranthoides Section Sexalaria Begonia annobonensis Section Cristastemen Begonia thomeana
	Begonia ampla

References

Key to species

1.	Junction of petiole and leaf blade with a tuft of hairs.	7. Begonia annobonenensis
1.*	Junction of petiole and leaf blade without a tuft of hairs.	2

2.	Flowers with 2 perianth segments	3
2.*	Flowers with 4 perianth segments	6

3.	Ovary and fruit winged.	8. Begonia thomeana
3.*	Ovary rounded, berry-like, not winged.	4

4.	Inflorescence cupped by large bracts making only the flower visible.	3. Begonia ampla
4.*	Large bracts cupping inflorescence absent, axis of inflorescence and peduncle visible.	5

5.	Plants densely hairy on the stems, petioles, peduncles, axis of the inflorescence, ovaries and fruits. Pedicels not elongated in fruit.	2. Begonia crateris
5.*	Plants sparsely hairy. Pedicels elongated in fruit.	1. Begonia baccata

6.	Ovary and fruit square or angled in cross section.	6. Begonia loranthoides
6.*	Ovary and fruit round in cross section.	7

7.	Leaf margin red. Flowers ca. 5 cm long.	5. Begonia subalpestris
7.*	Leaf margin green. Flowers ca. 2.5 cm long.	4. Begonia molleri

Key to some diagnostic characters

1. Tuft of hairs present at junction of blade with petiole – B. annobonensis

2. Fruits

a) Fruits winged – B. annobonensis, B. thomeana

b) Fruits not winged – B. ampla, B. baccata, B. crateris, B. molleri, B. subalpestris, B. loranthoides

3. Fruits square or angled in cross section – B. loranthoides

4. Tepal number

a) Flowers with 4-6 perianth segments – B. molleri, B. subalpestris, B. loranthoides, B. annobonensis

b) Flowers with 2 perianth segments – B. thomeana, B. baccata, B. crateris, B. ampla

5. Red leaf margin present – B. subalpestris

Description of species

Section Baccabegonia

1. Begonia baccata Hook. f.

Terrestrial or rupestral. Erect, rarely pendant. Leaves occasionally subpeltate or peltate, indument of peltate denticulate to stellate hairs; leaf margin not red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence bisexual, large cup-like bracts absent. Flowers white. Male flowers with 2 perianth segments, anthers dehiscing by longitudinal slits. Female flowers with 2 perianth segments, styles 4-7, forked, stigma spirally twisted. Ovary globose to sub-globose, not winged. Fruit berry-like, dehiscent, yellow to orange-red, erect. (Adapted from Reitsma 1985).

Distribution. Endemic to São Tomé.

Local distribution. São Tomé: Monte Rosa, Porto Alegre, S. Pedro, Monte Café and Pic de São Tome, Nova Moka, Lagõa Amelia, Ribeira Peixe, Juliana de Sousa, Binda, S. Nicolau, Santa Catarina, between Bassalar and Quija, Vanhulst, between Diogo Vaz and Santa Catarina, Traz-os-Montes, Praia Grande, Bom Successo, between Ermelinda and Cacumbé, Monte Palissoto.

Altitude. 0-1500 m.

Habitat. Near ocean shore and water courses, often found in forest edges and in more open forest like secondary forest and old plantations.

The photograph shows a somewhat atypical form of B. baccata, the undersides of the leaves having a reddish hue.

2. Begonia crateris Exell

Terrestrial or rupestral. Erect. Leaves peltate, indument of peltate denticulate to stellate hairs (indumentum dense compared to B. baccata); leaf margin not red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence bisexual, large cup-like bracts absent. Flowers white. Male flowers with 2 perianth segments, anthers dehiscing by longitudinal slits. Female flowers with 2 perianth segments, styles 4-6, forked, stigma spirally twisted. Ovary globose to sub-globose, not winged. Fruit berry-like, dehiscent, orange-red, erect. (Adapted from Reitsma 1985).

Distribution. Endemic to São Tomé.

Local distribution. São Tomé: Lagõa Amelia, Boa Enrada and surroundings, Calvario, Traz-os-Montes.

Altitude. 900-1500 m.

Habitat. Higher mountain region, rocky places near watercourses.

Note: B. crateris and B. baccata differ principally in the indumentum which is much denser in B. crateris particularly the stems, petioles, peduncles, axis of the inflorescence, ovaries and fruits. Another important difference are the leaves which are generally peltate in B. crateris and not so in B. baccata.

Section Squamibegonia

3. Begonia ampla Hook. f.

Epiphyte or rupestral. Leaves not peltate, indument of peltate dentate or stellate hairs; leaf margin not red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence bisexual, cupped by large bracts. Flowers pinkish or white. Male flowers with 2 perianth segments, anthers dehiscing by longitudinal slits. Female flowers with 2 perianth segments, styles 4, forked, stigma spirally twisted. Ovary obovoid, large, not winged. Fruit fleshy, indehiscent, whitish, held within the cup –like bracts. (Adapted from de Wilde & Arends 1980).

Distribution. Cameroon, São Tomé, Principe, Annobon, Bioko, Gabon, Congo, Zaire, Rwanda and Uganda.

Local distribution. São Tomé: Porto Alegre, Monte Rosa, Praia Grande, between Binda and Juliana de Sousa, Nova Moka, Angra de S. João, between Preserverança and Novo Brasil, Santo Antonio, between Quija and Chufe-Chufe. Principe: between Terreiro Velho and Infante D. Henrique, Infante D. Henrique.

Altitude. 0-1800 m.

Habitat. Primary and secondary forest. Often found as epiphytic on trees near watercourses.

Section Tetraphila

4. Begonia molleri (C.D.C.) Warb.

Epiphyte. Monoecious. Leaves not peltate, indumentum absent; leaf margin not red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence unisexual. Flowers white. Male flowers with 4 perianth segments, anther dehiscence unknown. Female flowers with 4 perianth segments, styles 4, forked, stigma spirally twisted. Ovary fusiform, not winged, round in cross section. Fruit dehiscent.

Distribution. Endemic to São Tomé.

Local distribution. Between Monte Café and the Pico, Nova Moka.

Altitude. 850 m.

Habitat. Unknown.

Epiphyte. Probably dioecious. Leaves not peltate, indument absent or sparse of peltate dentate or stellate hairs; leaf margin red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence unisexual. Flowers pink-and-white. Male flowers with 4 perianth segments, anther dehiscence unknown. Female flowers with 4 perianth segments, styles 2-3, forked, stigma spirally twisted. Ovary fusiform, round in cross section, not winged. Fruit dehiscent, more or less erect.

Distribution. Endemic to São Tomé.

Local distribution. Vanhulst, Calvario, to the east of the Pico.

Altitude. 1080-1550 m.

Habitat. Unknown.

6. Begonia loranthoides Hook. f. subsp loranthoides

Epiphyte or rupestral. Leaves not peltate, indument of peltate dentate or stellate hairs; leaf margin not red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence unisexual. Flowers pink to white. Male flowers with 4 perianth segments, anthers dehiscing by longitudinal slits. Female flowers with 4 perianth segments, styles 4-6, forked, stigma spirally twisted. Ovary fusiform or club-shaped, not winged, square in cross section. Fruit dehiscent, erect. (Adapted from de Wilde & Arends 1979).

Distribution. Endemic to São Tomé and Principe (other subspecies found on mainland Africa).

Local distribution. São Tomé: the Pico, Traz-os-Montes. Principe:Porto Real, Infante D. Henrique, on slopes towards Neves Ferreira.

Altitude. 750-1800 m.

Habitat. Mist forest region on São Tomé.

Section Sexalaria

7. Begonia annobonensis A. DC.

Terrestrial or rupestral. Erect. Leaves not peltate, indument of simple hairs; leaf margin not red; junction of petiole and leaf blade with a tuft of hairs. Inflorescence bisexual, not cupped by large bracts. Flowers white or pink. Male flowers with 4 perianth segments, anthers dehiscing by longitudinal slits. Female flowers with 4-6 perianth segments, styles 3, bilobed, stigma kidney-shaped. Ovary 3-7-winged, wings unequal. Fruit dehiscent, more or less erect. (Adapted from Doorenbos et al. 1998).

Distribution. Coastal Cameroon, São Tomé, Principe and Annobon.

Local distribution. São Tomé: Praia das Sete Ondas. Principe: Sundí.

Altitude. Sea level.

Habitat. On rocks near shore, stream gorges.

Section Cristastemen

8. Begonia thomeana C.D.C.

Terrestrial, climber. Leaves not peltate, indumentum of simple hairs; leaf margin not red; junction of petiole and leaf blade without a tuft of hairs. Inflorescence bisexual, not cupped by large bracts. Flowers yellow to orange. Male flowers with 2 perianth segments, anthers dehiscing by longitudinal slits. Female flowers with 2 perianth segments, styles 3, forking several times, stigma crescent shaped. Ovary 3-winged, one wing larger than the other two. Fruit dehiscent, pendulous. (Adapted from Doorenbos et al. 1998).

Distribution. São Tomé and Gabon.

Local distribution. São Tomé: between Monte Café and Pico; near Vanhulst; Traz-os-Montes; Rio Contador (from Exell).

Altitude. 950-1230 m.

Habitat. Forest.

References

Doorenbos, J., M.S.M. Sosef & J.J.F.E. de Wilde. 1998. The Sections of Begonia – Studies in Begoniaceae VI. Wageningen Agric. Univ. Papers 98 (2): 5-266.

Reitsma, J.M. 1985. Begonia section Baccabegonia Reitsma, sect. nov. – Studies in Begoniaceae II. Wageningen Agric. Univ. Papers 84(3): 95-111.

Wilde, J.J.F.E. de & J.C. Arends. 1979. Begonia loranthoides Hook. f. (Sect. Tetraphila A. D.C.). Acta Bot. Neerl. 28(4/5): 357-374.

Wilde, J.J.F.E. de & J.C. Arends. 1980. Begonia section Squamibegonia Warb.: a taxonomic revision. Misc. Papers Landbouwhogeschool Wageningen 19: 377-421.

Top of Page

Botanical Contents Page

Home Page