Mendoncia gilgiana subsp. occidentalis, Breteler & Wieringa. Fruit, 2018

Breteler, F. J. & Wieringa, J. J., 2018, A synopsis of Mendoncia (Acanthaceae) in continental Africa including the description of two new species from western Central Africa and a new subspecies from West Africa, Blumea 63 (2), pp. 109-119 : 114

– Bracteoles triangular-ovate, cordate at base, (15–)17–20 (–22) by 14–15 mm; part of pedicel above attachment of bracteoles ≥ 1.5 mm long. — Guinea, Liberia, Ivory Coast, Ghana....................... b. subsp. occidentalis a. subsp. gilgiana — Fig. 3a ; Map 4

Mendoncia gilgiana Lindau (Benoist) var. tisserantii Benoist (1939) 679; Heine (1963) 403; Hawthorn & Jongkind (2006) 442, p.p. — Type: Tisserant 2055 (holo P), Central African Republic, Ouaka region, 20 km N of Bambari, 10 Oct. 1925.

Habitat & Distribution — Semi-deciduous forests in Cameroon, Central African Republic, Equatorial Guinea, Gabon, Congo (Brazzaville), Congo (Kinshasa), South Sudan, Uganda, Kenya, Tanzania. Altitude 300–1570 m. See notes.

Conservation status — With an EOO of 2 859 240 km 2 and an AOO of 448 km 2 but from a range of countries and partly from protected areas resulting in many different locations, this subspecies is considered as Least Concern (LC).

Notes — Benoist distinguished M. gilgiana var. tisserantii from the type variety by the hairiness of its branches, petioles, and bracteoles, being ‘parce pilosis’ in contrast to the densely hairy type specimen. Heine (1963), followed by Hawthorn & Jongkind (2006) described M. gilgiana specimens from West Africa as entirely glabrous and classified them under var. tisserantii . The type of var. tisserantii originates from the eastern part of the distribution area of M. gilgiana where sparsely hairy specimens do occur, but we have never seen a single glabrous one from that area. In his treatment of Mendoncia for the Flore du Gabon, Heine (1966) did not maintain var. tisserantii as a distinct taxon, nor was it recognised by Magnaghi & Daniels (2017).

Magnaghi & Daniel (2017) claim to have seen only photographs of this taxon from southern Congo (Kinshasa) and discuss how it might be distinct. However, at least one of the specimens they cite ( Callens 3436, from Panzi) is also from that area, but they have mapped this specimen to another location named Panzi, and they did not see several other collections of this species in BR.

The distribution of M. gilgiana subsp. gilgiana in western Central Africa , notably in Gabon , is, so far, restricted to the area north of the equator. The only collection from this country is from Mé- kambo in the northeast where the forests are semi-deciduous in contrast to the more evergreen forests in west and central Gabon . In the adjacent Congo (Brazzaville) M. gilgiana subsp. gilgiana is known from three collections: Mildbraed 3820 from Likilambe on the Sangha river and Ndolo Ebika 198 and 906 collected SE of Bomassa respectively at Bomassa. Further eastwards, in Congo (Kinshasa) , the subspecies gilgiana is known from a much larger area, from above and below the equator, up to an altitude of 1 400 m. The distribution pattern in Gabon and eastwards would suggest the species evades the wettest forests, however, in Cameroon it seems to occur also in the wetter parts, but always above 500 m altitude, possibly in areas with a rain shadow. Also , in Cameroon it has not been found in the wettest areas like around Kribi and Mt Cameroon .

Figures

Map 4 Distribution of Mendoncia gilgiana (Lindau) Benoist; subsp. gilgiana (●); subsp. occidentalis Breteler & Wieringa (■).

Fig. 3 a.Mendoncia gilgiana (Lindau) Benoist subsp.gilgiana. Fruit with one bracteole removed. — b. Mendoncia gilgiana (Lindau) Benoist subsp. occidentalis Breteler & Wieringa. Fruit with one bracteole removed (a: F.J. Breteler 767, WAG; b: X.M. v.d. Burgt 1290, WAG). — Drawing by Hans de Vries.