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Published In: 189, pl. 9A. 1944. Name publication detail
 

Project Name Data (Last Modified On 12/8/2019)
Acceptance : Accepted
Taxon Profile     (Last Modified On 10/26/2021)
Description : Herb with woody stem, white to brown, large lenticels; height of up to 4 m and a leaf diameter of 50 cm. At end of stem large leaves with inflorescences. Stalks and petioles with brown hairs. Peltate leaves, herbaceous, brown hairs on both sides, bright green and half glossy, protruding veins above, lighter green below. Inflorescences regularly built up, male flowers bloom before female flowers. Flower buds with two transparent red bud scales. Male flower: 2 white petals with red dots, white filament, yellow anthers. Female flower: two white petals with red dots, pistil yellow. Fruits at first light brown, hairy, when ripe red-brown, smoother. The placentation is septal in the whole ovary and the ovary is (4-)5(-6)-locular. There are (2-)4 placentae per septum and these are very capriciously shaped. The number of ovules per section amounts to 250-300. The ovary is roundish in circumference. The mature fruits dehisce by (4-)5(-6) valves (Reitsma 1983).
Habitus : Herb, Shrub up to 7 m
Phenology : Flowers have been observed in october and november, fruits in november.
Habitat : Known from submontane and montane rainforest, usually in half-open areas, between 800 and 2,020 m in elevation.
Distribution : São Tomé (endemic)
Distribution Note : The species is endemic to São Tomé island. It is known from 21 collections made between 1905 (Chevalier #13748) and 2020 (Lima #58) in the north and north-centre of the island. Fourteen collections were made in the Obô National Park (PNOST), most of them in or around Lagoa Amelia.
Note : This species needs taxonomic clarification. Begonia crateris, is morphologically very similar to B. baccata, and suggestions have been made to merge the two species (Ferreira 1965). Reitsma (1985) differentiated them by the heavier indumentum of B. crateris and by contrasting positions of the petiole (leaves petiolate in B. crateris) and stamens (Plana, 2002). Thus, the lack of collection since 1978 would be due to the confusion of these two species, especially in Lagoa Amelia where botanical harvests have been intense in recent years. However, the two species are distinguished by local people in the field.
More literature : Ferreira, J.H.P. 1965. Begoniaceae de S. Tomé e Principe. Garcia de Orta (Lisboa) 13: 525-544., Plana, V. 2002. Systematics and biogeography of the Afro-Malagasy fleshy-fruited Begonia (Begoniaceae). Doctoral dissertation, ProQuest Dissertations & Theses., Reitsma, J.M. 1983. Placentation in Begonias from the African continent; Studies in Begoniaceae I. Mededelingen van de Landbouwhogeschool Wageningen 83(9): 21-53., Reitsma, J.M. 1985. Begonia section Baccabegonia Reitsma, sect. nov. Agricultural University Wageningen Papers 84(3): 95-111.
Case Study : São Tomé

Conservation assessment     (Last Modified On 10/26/2021)
Red List Category : Endangered
Status of Conservation Assessment : Submitted to Red List
Assessment rationale : Begonia crateris is a shrub up to 4 m high. It has been suggested that it might be synonymous with B. baccata (Ferreira, 1965) but Reitsma (1985) and Plana (2002) considered it as a distinct species, a view supported by recent fieldwork. One collection (Chevalier #13748) was made around Boa Entrada (300 m in elevation). Based on lower elevation and degradation of habitat at Boa Entrada, we consider that this collection probably represents a cultivated subpopulation, and whether the occurrence still exists is not clear. So, this collection was excluded from this assessment. The 20 remaining collections represent 11 occurrences, none of which are considered as extirpated. Three occurrences are located in the area of Roça Calvàrio, outside of the PNOST. The seeds are dispersed by birds (Plana, 2002), so these 11 occurrences represent 1 or 2 subpopulations. Based on a 2 x 2 km cell size, the area of occupancy (AOO) of this species is estimated to be 24 km2, below the upper threshold for “Endangered” status under subcriterion B2. The extent of occurrence (EOO) is calculated as 34.516 km2, below the upper threshold for “Critically Endangered” status under subcriterion B1. The five occurrences along the tourist path are threatened by ecotourism, and represent one location. Two occurrences around Lagoa Amelia (within PNOST), and three others around Macambrará (outside of the protected area), are both threatened for traditional medicinal use, especially at Lagoa Amelia. Indeed, leaves of this species are used to make a tea to prevent abortion and local people often cut leafy stems from adult individuals. The three occurrences located around Macambará are also threatened by illegal forest logging that affects the species’ habitat. Despite they occur within and outside PNOST, the five occurrences (Macambará and Lagoa Amelia) are affected simultaneously by a given and represent one location. The occurrence of Monte Cabumbé is not threatened and represents one location. Consequently, these 11 occurrences represent three locations (sensu IUCN, 2019), with regard to the most important threat (traditional medicinal use) which induces a continuing decline in the number of mature individuals by cutting adult individuals. We also infer a past, current and future continuing decline in the extent and habitat quality. This species is thus assessed as Endangered (EN) B1ab(iii,v)+2ab(iii,v).

 


 

Specimens whose coordinates are enclosed in square brackets [ ] have been mapped to a standard reference mark based on political units.
 
 
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