The genus Hyphaene (apparently 8 spp.) is distributed in dry regions of continental Africa, Madagascar, the Red Sea region, and the coasts of the Gulf of Eilat, Arabia and western India (Fig. 1). The southernmost limit of the genus (28° S) is apparently reached in the South African province of Kwazulu-Natal (H. coriacea). One species reported from Sri Lanka may be an introduction (Furtado, 1970b; Dransfield et al., 2008), but this hypothesis needs to be confirmed. Species of Hyphaene commonly grow in sandy lowlands, open secondary forests and inland or coastal savannahs, although some species are also present in the riverine forest. The genus has been reported to grow from sea level up to 1400 m. Elephants and baboons, among other wild animals, disperse the seeds, and bees visit the flowers (Dransfield et al., 2008). Highly adapted to dry and xeric conditions, H. thebaica may be an invasive palm in Curaçao, in the West Indies (Delnatte, 2003). In the lowlands of western Madagascar human activity has favored the establishment of palm savannahs, with H. coriacea cited among the palms able to survive fire in annually burned grassland (Dransfield and Beentje, 1995). This species has been also reported behaving as a pioneer stabilizer of mobile dunes in Kenya. According to Pritchard et al. (2004) large-seeded, drought-tolerant species such as H. petersiana may have evolved thick seed coats or endocarps to reduce losses due to seed predation.
Factors affecting seed germination have been studied for H. petersiana and H. thebaica (Davies & Pritchard, 1998; Moussa et al., 1998; Yusef, 2007). A survey on the biology and ecology of H. compressa in the Meru National Park (Kenya) was provided by Angaine (2005), as a Master’s thesis, but has not yet been published. Blach-Overgaard and Balslev (2009) evaluated the sensitivity of the African ivory-nut palm H. petersiana to climate change, in light of the profound changes that are projected for south-western Africa.
Fig. 1. Distribution area of Hyphaene; wild populations are restricted to dry lowlands. Populations in Oman not marked as this record needs confirmation (adapted from Dransfield et al., 2008).
Hyphaene compressa is present in 5 countries: Ethiopia, Kenya, Mozambique, Somalia and Tanzania
Hyphaene coriacea is present in 9 countries: Ethiopia, Kenya, Malawi, Namibia and Mozambique, Somalia, South Africa and Tanzania. This species is also present in Madagascar (Dransfield and Beentje, 1995)
Hyphaene dichotoma is endemic to India (Guyjarat, Maharashtra). Possibly occurring farther south in India, perhaps to Goa (Henderson, 2009)
Hyphaene guineensis is present in 8 countries: Angola, Congo, Gabon, Ghana, Guinée, Guinée Bissau, Liberia and the Republique Démocratique du Congo
Hyphaene macrosperma is endemic to Benin
Hyphaene petersiana is present in 8 countries: Angola, Burundi, Namibia, Mozambique, Republique Démocratique du Congo, Rwanda, Tanzania and Zimbabwe
Hyphaene reptans is present in 2 countries: Kenya and Somalia
Hyphaene thebaica is present in 21 countries: Benin, Burkina-Faso, Cameroon, Chad, Côte d'Ivoire, Djibouti, Egypt, Eritrea, Ethiopia, Gambia, Ghana, Mali, Mauritania, Niger, Nigeria, République Centroafricaine, Senegal, Sierra Leone, Somalia, Sudan and Togo. The species is also present in the Red Sea region, and the coasts of the Gulf of Eilat, Arabia (Dransfield et al., 2008)
Our current knowledge on the distribution of Hyphaene highlights that H. thebaica is the best represented species whereas H. macrosperma and H. dichotoma have only been reported to one country.
Fig. 2. Distribution of the seven Hyphaene species present in Continental Africa. According to Dransfield and Beentje (1995) Hyphaene coriacea is also present in Madagascar. Data based on Stauffer et al. (2014)