Sclerosperma profiziana

Sclerosperma (sklehr-oh-SPEHRM-ah) profiziana (proh-fee-zee-AHN-ah)
French Guiana. Near Cayenne. Photo by Pierre-Olivier ALBANO.
Scientific Classification
Genus: Sclerosperma (sklehr-oh-SPEHRM-ah) Species: profiziana (proh-fee-zee-AHN-ah)
Synonyms
None set.
Native Continent
Africa
Morphology
Habit: Solitary Leaf type: Pinnate
Culture
Survivability index
Common names
Tua (Zima, Ghana), Tu (Lari, Téké, Soundi, Congo [Brazzaville] Pool), Tuu (Bambenga, Congo [Brazzaville] Pool), Mabondo (Congo [Kinshasa], Bas-Congo), Mangobo (Congo [Kinshasa], Maniema).

Habitat and Distribution

Angola, Congo, and Nigeria. Sclerosperma profiziana has a clearly disjunct

French Guiana. Near Cayenne. Photo by Pierre-Olivier ALBANO.

distribution with a population in southwest Ghana, and the other population in the larger tributary of the Congo River. A photographic record for southeast Nigeria of a Sclerosperma with undivided or minimally bifid leaves (Tuley 1995) is not corroborated by a herbarium voucher and so its presence in Nigeria is awaiting confirmation. Sclerosperma profiziana is found on relatively dry patches in swampy areas, in valley bottom forest, in forest that is often waterlogged or along streams.

Description

Short or acaulescent, clustering palm to 6 (- 12) m height. Stem if evident, 1 - 2 m tall, rather stout, closely ringed with leaf scars. Leaves, undivided, very large, deeply bifid in juveniles, ascending; sheath to 40 cm, splitting opposite the petiole, margins fibrous; petiole robust, 60 - 100 (- 400) cm long, adaxially channelled, abaxially rounded proximally, becoming triangular distally; rachis 150 - 200(- 450) cm long, abaxially rounded, adaxially with a prominent ridge, blade elongate-cuneate in outline, 20 - 60(- 140) cm at its largest width, undivided except for the bifid apex where the rachis is continued in a fibre and the margins are up to 15 cm long, blade adaxially shining dark green, abaxially glaucous and with small scales along the veins, margins minutely toothed, transverse veinlets not evident. Inflorescence solitary, interfoliar, concealed among the leaf bases and sometimes partially obscured by accumulated debris, spicate; peduncle to 15 cm long, elliptic in cross-section to 3 cm wide, densely tomentose; prophyll to 23 cm long; peduncular bract to 45 cm long; rachis at anthesis to 25 cm long, stout. Staminate flowers sepals 3, distinct 5 × 6 mm; petals 3, distinct 5 - 8 × 11 - 15 mm, obovate to elliptical; stamens c. 100, filaments very short, ± triangular, anthers elongate; pistillode lacking. Pistillate flowers larger than the staminate, broadly ovoid; sepals 3, connate in a 3-lobed, glabrous cupule or margins of two sepals distinct and imbricate, somewhat angled by mutual pressure; petals 3, distinct, asymmetrical. Rachis of infructescence 6 - 10 cm long, bearing up to 30 fruits. Fruit globose to obovoid, 3 - 3.5 × 3.8 - 4 cm to 4 - 4.5 × 2.5 - 3 cm (not yet mature). Seed globose to obovoid 3 × 3.5 cm to 3.5 × 3 cm. (John Dransfield 2008. A revision of the genus Sclerosperma (Arecaceae). Kew Bulletin 63: 75-86)/Palmweb. Editing by edric.

Sclerosperma with undivided leaves was considered as a mere aberrant form of S. mannii in Anglophone taxonomic literature (Russell 1968). The circumscription of S. mannii in the ?Flora of tropical West Africa' was therefore very broad, accommodating the variation in leaf shape and the occasional formation of a small trunk, as observed in southwest Ghana. This species concept was also adopted for the ?Genera Palmarum' treatment (Uhl & Dransfield 1987), despite the astonishing pictures of two extremely different leaf shapes (p. 149) based on the collections by Moore in Ghana and Gabon in 1971 (Moore 1971). However, in Francophone literature the name ?mabondo' emerged in the beginning of the 20th century to describe a Sclerosperma with undivided leaves from the Congo tributary. This name was used as a species epithet and ascribed to De Wildeman, although he never validly published this name. In 1990 and 1991, Jean-Pierre Profizi made elaborate collections of a Sclerosperma with undivided leaves in Congo (Brazzaville). He subsequently linked his material to ?S. mabondo?, prepared a taxonomic treatment of the species and made a first attempt to revise of the genus Sclerosperma. However, his manuscript was never published. The fertile collections available for Ghana are very limited. The inflorescences at male anthesis (Hall & Enti GC 36150) appear to be of much more modest dimensions than those of specimens available from Congo. No fruit collections from Ghana are known and, as the infructescence is obviously accrescent, this further hampers delimitation of the species. We therefore consider all collections with undivided leaves that originate from Ghana and the larger Congo tributary to belong to the same species. The material stored in a box at BR (with the external label ?Gillet 279') is a mixture of various collections, which apparently arrived at different dates. Two sheets, one with field tag 279, the other with an apparent original field label 279, were collected in 1899 (and probably arrived at BR in 1900); these represent a Sclerosperma with divided leaves, identified as S. walkeri. A third, (at present) unmounted, ?sheet' in a cover represents a Sclerosperma with undivided leaves. The species represented by this collection was apparently locally called Mabondo: a separate piece of paper states, ?elements botaniques du Sclerosperma sp. ?Mabondo' du frère Gillet de Kisantu pour le Jar Bot de Bruxelles?. This leaf strongly resembles the two duplicates of 279 present at K and WAG; on the K and WAG sheet, the collection date mentioned is 1913, but this date does not figure in the BR box. In the K and WAG duplicates, two inflorescences are present; similar inflorescences are found in the BR box. These inflorescences, the single cover sheet with undivided leaf at BR, and the K and WAG duplicates are renumbered to 279a. Also present in the box at BR is a linen bag with a label mentioning the vernacular name ?Niagangu/Magangu', numerous kernels, a single fruit that fits exactly in an unlabelled infructescence, and an unlabelled infructescence with mature fruits attached. This material is renumbered as Gillet s. n. and identified as S. walkeri. (John Dransfield 2008. A revision of the genus Sclerosperma (Arecaceae). Kew Bulletin 63: 75-86)/Palmweb.

Culture

Cold Hardiness Zone: 11

Comments and Curiosities

Etymology: The species has been named after Jean-Pierre Profizi (8 June 1954 at Marseille) to acknowledge his efforts to clarify the status of this species.

Uses: The leaves are widely used for thatch, and preferred to the Sclerosperma with divided leaves. In general, smaller leaves are used for thatch, as these are not yet damaged by the wind. In former times, the hard kernel was used to make rings and has been the subject of studies for its use as vegetable ivory for button manufacturing.

Conservation: Although this species is geographically locally common, it is highly localised with many geographical disjunctions. As such we suggest that, while the species may be classified as Lower Risk within the sub-category Near Threatened, given the extent of habitat loss throughout its range, particularly in West Africa, it could become Vulnerable in the medium-term future.