Hyphaene petersiana

Hyphaene petersiana Klotzsch ex Mart., Hist. Nat. Palm. 3(ed. 2): 227 (1845); Fl. Trop. E. Africa, Palmae: 24 (1986); Palm. Afr. 29 (1995); Checklist Zimbabwean vasc. pl. 33: 85 (2004); Tree Atlas Namib. 38 (2005); Checklist Zambian vasc. pl. 32: 106 (2005); Strelitzia 22: 172 (2008); Fl.Zambes. 13(2): 53 (2010). – Icon.: Fl. Trop. E. Africa, Palmae: 25, 154-156 (1986); Tree Atlas Namib. 39 (2005); Fl. Zambes. 13(2): 54 (2010).

Synonyms: Chamaeriphes benguelensis (Welw. ex H. Wendl.) Kuntze; C. ventricosa (J. Kirk) Kuntze; H. aurantiaca Dammer; H. benguelensis Welw. ex H. Wendl.; H. benguelensis var. ventricosa (J. Kirk) Furtado; H. bussei Dammer; H. goetzei Dammer; H. obovata Furtado; H. ovata Furtado; H. plagiocarpa Dammer; H. ventricosa J. Kirk; H. ventricosa subsp. ambolandensis Becc.; H. ventricosa subsp. anisopleura Becc.; H. ventricosa subsp. aurantiaca (Dammer) Becc.; H. ventricosa subsp. benguelensis (Welw. ex H. Wendl.) Becc.; H. ventricosa subsp. bussei (Dammer) Becc.; H. ventricosa subsp. goetzei (Dammer) Becc.; H. ventricosa subsp. petersiana (Klotzsch ex Mart.) >Becc.; H. ventricosa subsp. plagiocarpa (Dammer) Becc.; H. ventricosa subsp. russisiensis Becc.; H. ventricosa subsp. useguhensis Becc.

Palm solitary, armed, pleonanthic, dioecious.

Stem 15-20 m tall and 35-50 cm in diameter, solitary (Figs. 1-3), straight or slightly swollen at 10-12 m above ground.

Leaves 20-26, costapalmate ; leaf sheath 40 cm long, with a longitudinal middle cleft of 20 cm, with spiny margins; petiole 1.5-1,8 m long, 10-16 cm wide at the base and 7-8 cm wide towards the apex; hastula irregular, 10 cm long; costa 1,1 m long, strongly recurved; leaf blade divided in 74-77 regular segments; basal segments 70-95 cm long, middle segments 1,7-1,9 m long, apical segments 0.85- 1 m long (Figs. 4, 5)

Inflorescences interfoliar, unisexual, pistillate and staminate inflorescences barely similar. Male inflorescence up to 5 in the same individual and at different stages of development; peduncle 30-40 cm long, 10 cm wide; rachis 1,2 m long; rachillae, each topped by 5 reproductive branches. Female inflorescence with a peduncle 50 cm long; rachis 90 cm long, bearing 12 rachillae.

Fruits oblong, rounded, obovoid or ovoid,  5-10 cm long and 5-6,5 cm wide, red-brown to chestnut, shiny when polished (Figs. 6-8); eophyll linear, lanceolate, plicate.

Hyphaene petersiana grows in the savannah or in secondary vegetation; it grows on sodic-saline alluvial soils with high water tables. In East Africa it grows in inland regions, usually confined to alkaline soils with relatively high water-tables; it is distributed from see level to 1300 m.

This species is sometimes confused with Borassus aethiopum, the two taxa being easily distinguished by the well-defined petiole-spines in Hyphaene petersiana vs. erose spines in Borassus, and the elongate pointed segments in Hyphaene vs. the stiffer, broader, more rounded segments in Borassus (Dransfield, 2010).This species is distributed in Tanzania, occurring from Lakes Manyara and Eyasi southwards; common throughout the Zambesi region, reaching N. Transvaal, through the Democratic Republic of Congo to the West coast of Africa in Angola and Namibia.The leaves of this palm are intensively collected for basket weaving and as documented by Dijkman (1999) this may represent a threat for wild populations in southern Zimbabwe.

The conservation status of this species has been recently assessed by Cosiaux et al. (2017) and the category of Least Concern (LC) has been proposed. You can get detailed information on this assessment by clicking in the following link: http://www.iucnredlist.org/details/95317629/0

Fig. 1. Stand of Hyphaene petersiana in the village of Mikoche, on the shores of the Lake Eyasi (Tanzania, Arusha Region). This palm has a solitary growth habit and the stems reach up to 12 m. The “ventricose” stems were only observed in some individuals, most often males. 

Fig. 2. Inland savanna dominated by Hyphaene petersiana. Note individuals at different stages of development. Tanzania, Lake Eyasi (photo Didier Roguet)

Fig. 3. Growth habit of Hyphaene petersiana. Note the abundant remnant leaf sheaths attached on the stem. Tanzania, Lake Eyasi (photo Didier Roguet)

Fig. 4. Detail of leaf crown and leaf sheaths in Hyphaene petersiana. Note the abundant male inflorescences emerging from the leaf axes. Tanzania, Lake Eyasi (photo Fred Stauffer)

Fig. 5. Detail of leaf blade in Hyphaene petersiana. Note the costa and the strongly armed petiole margins. Tanzania, Lake Eyasi (photo Didier Roguet)

Fig. 6. Detail of ripe infructescence in Hyphaene petersiana. Tanzania, Lake Eyasi (photo Didier Roguet)

Fig. 7. Infructescence of Hyphaene petersiana bearing the regularly oblong, shiny fruits, typical of the species (Tanzania: village of Mikoche, on the shores of the Lake Eyasi, Arusha Region).

Fig. 8. Detail of ripe fruit (cross section) in Hyphaene petersiana. Tanzania, Lake Eyasi (photo Didier Roguet)


 Fig. 3. Distribution of Hyphaene petersiana (based on Stauffer et al., 2014)