Talbotiella velutina Burgt & Wieringa

Mackinder, B.A., Wieringa, J.J. & van der Burgt, X.M. 2010. A revision of the genus Talbotiella Baker f. (Caesalpinioideae: Leguminosae). Kew Bulletin 65: 401. DOI: https://doi.org/10.1007/s12225-010-9217-0

Type

Cameroon, Korup National Park, PE plot near P transect, subplot 16ZN, tree number PE8123, 5°01'N 8°48'E, alt. c. 100 m, 15 Oct. 2005, van der Burgt & Eyakwe 777 (holotypus WAG; isotypi B, BR, G, K, MA, MO, P, SCA, US, YA).

Morphology General Habit

Tree 26 - 35.3 m, dbh 22 - 76 cm; bole straight, vertically lobed or fluted along its entire length, sometimes with steep buttresses, up to 2.5 m high and c. 1 m wide; bark smooth, pale light brown

Morphology Stem

Stems moderately pubescent, hairs to c. 1.5 mm long

Morphology General Buds

Bud scales up to 15, distichous, caducous, coriaceous, not keeled, outer surface moderately puberulous, at least towards the edges, margins ciliate, inner surface glabrous, light brown-green with reddish edges (when fresh), uniformly brown when dried, proximal scales suborbicular, c. 1.5 - 2 mm diam., distal scales becoming progressively longer and relatively narrower, on branches in leaf flush apical scale obovate, c. 23 - 18 mm, not keeled; on inflorescence branch apical scale to 9 - 10 mm

Morphology Leaves Stipules

Stipules (seen in young foliage) in pairs, free, auriculate at base, the auricle suborbicular, to 6 - 3 mm, margins ciliate, upper part of stipule narrowly lanceolate, 15 - 20 (- 28) x 2 (- 3) mm, apex acute, outer surface and margins appressed pubescent, inner surface glabrous

Morphology Leaves

Leaves alternate, paripinnate, 5.2 - 11 (- 17.5) x 2.4 - 4.3 (- 5.1) cm; petiole 2 - 4 mm long, leaf rachis 4.4 - 9.8 (- 15.6) cm long, sparsely to moderately pubescent, leaflets sessile, in 14 - 22 pairs, upper and middle leaflets opposite, lower 3 - 4 pairs sub-opposite, (7 -) 13 - 24 (- 32) x (2 -) 4 - 6 (- 8) mm, narrowly oblong, base asymmetric, proximal margin tapering towards apex, apex rounded, glabrous above except for pubescent midvein, lower surface sparsely appressed puberulous, barely visible with a hand lens but visible under a microscope, fringing hairs c. 2 mm long, on the lower margins of young leaflets but absent from seedling and mature leaflets; midvein central, prominent above and below for most of its length, becoming obscure just before the apex, in leaflets 0 - 4 (- 7) small glands present, not visible with a hand lens but visible with a microscope, on the distal half of the lower surface, commonly positioned about midway between the midvein and margin

Morphology Reproductive morphology Inflorescences

Inflorescence an 8 - 20-flowered raceme, axis 16 - 52 mm long including a peduncle 8 - 15 mm long, peduncle and rachis with a dense indumentum of golden sericeous hairs, 1 - 1.5 mm long

Morphology Reproductive morphology Inflorescences Bracts

Floral bracts often caducous, obovate to spathulate, 7 - 10.5 x 1.5 - 3 mm, outer surface moderately to densely appressed pubescent, upper margins ciliate but margins often glabrous in the lower half, inner surface glabrous; pedicels white, moderately to densely crinkly patent hairs to 1.2 mm long, portion of pedicel below bracteoles 6 - 8 mm long; bracteoles white, opposite, linear to narrowly elliptic, 6 - 8 x 1 - 2 mm, densely appressed pubescent outside, glabrous inside, margins ciliate; portion of pedicel above bracteoles 3 - 4 mm

Morphology Reproductive morphology Flowers Hypanthium

Hypanthium narrowly campanulate, white, 1.5 mm deep, outer surface moderately patent pubescent, inner surface glabrous

Morphology Reproductive morphology Flowers Calyx

Sepals 4, white, cucullate, outer surface and margins sparsely and unevenly pubescent, inner surface glabrous, apex rounded; adaxial sepal c. 4.5 - 6 mm, lateral sepals c. 3 - 6 mm, abaxial sepal c. 4 - 6 mm

Morphology Reproductive morphology Flowers Corolla

Petals absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 10, filaments free, 8 - 10 mm long, white, glabrous or with some scattered hairs, anthers oblong-elliptic, 1.2 - 1.5 mm long, orange-brown

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary white, 2 - 3 x 1 mm, very densely covered with spreading golden pubescent hairs to 1.5 mm long, on a stipe 1 - 2 mm long, velutinous, fused to the adaxial side of the hypanthium, free part of stipe very short, less than 0.5 mm long, ovules 2, style 5 - 7 mm long, sparse long hairs on lower half, stigma capitate

Morphology Reproductive morphology Fruits Infructescences

Infructescence axis 16 - 30 mm long, retaining dense velutinous indumentum, 1 or 2 pods, usually at the top of the axis subtended by fruiting pedicels 11 - 15 mm, unevenly sparsely to moderately spreading pubescent

Morphology Reproductive morphology Fruits

Pod compressed, 4.8 - 8.9 x 2.4 - 3.9 cm, triangular, broadest towards apex, upper suture slightly broadened, 4 - 5 mm wide, surfaces and suture, moderately puberulous, beak 1 - 2 mm long

Morphology Reproductive morphology Seeds

Seeds 1 - 2 (0 in aborted pods); 1 - 1.5 cm diam., c. 3 mm thick

Seedling

Seedling: hypocotyl 4 - 6 cm, epicotyl 6 - 7.5 cm, first pair of leaves opposite, leaves 7.2 - 3.3 cm, leaflets in 12 pairs to 17 x 6 mm

Distribution

Cameroon, Southwest Province, Korup National Park and Besingi village forest.

Ecology

Lowland primary rainforest on well-drained sandy soil; 50 - 100 m. The rainfall at the Bulu weather station, c. 12 km southeast of the type locality, ranged from 4023 to 6146 mm/y, and averaged 5029 mm/y (1984 - 2004). The climate is strongly seasonal with one distinct dry season from December to February (average monthly rainfall less than 100 mm). Talbotiella velutina occurs in Caesalpinioideae-rich forest and was discovered in and near the P transect plots in the southern part of Korup National Park. The total size of these plots is 155.75 ha. Of the 3181 recorded trees > 50 cm trunk diameter, eight trees were identified as T. velutina. Trees with a trunk diameter of between 10 and 50 cm were registered in 56 randomly located subplots of 0.25 ha each, a total size of 14 ha. Of the 5755 recorded trees between 10 and 50 cm trunk diameter, none were identified to T. velutina. Around the eight trees of trees = 50 cm trunk diameter, but outside the subplots referred to above, some trees smaller than 50 cm diameter were found. Several groups of trees were found near the plots. In a forest near the village Besingi, 15 - 18 km from the other trees, a group of four trees was found. In total 39, trees of T. velutina were found.

Kew Species Profiles

General Description

Talbotiella velutina was found during the set-up of a permanent plot in Korup National Park in Cameroon, a piece of work supervised by Prof. David Newbery of the University of Bern. Only 35 trees were found inside or near this plot, though four trees of this species have also been found in the forest of the village Besingi.

Species Profile

Geography and distribution

This species has been found in Cameroon (Africa), where it occurs in the Southwest Province in two localities: Korup National Park and Besingi village forest.

Description

Talbotiella velutina is a tree of up to 35.3 m high, and up to 76 cm stem diameter.

The trees always grow in small groups, hence if one tree is found there are always a few other trees within a distance of about 50 m.

Due to the dimensions of this tree the flowers and fruits can only be collected by climbing with alpine climbing equipment, which can be a hazardous activity.

Threats and conservation

A total of 39 trees of this species have been found in remote parts of the Korup National Park and the Besingi village forest. Tourists seldom go there, but researchers sometimes visit the area.

Korup National Park is often visited by poachers who are slowly reducing the animal population of the park. This has serious consequences for the ecology of the vegetation in the park, and may affect the Talbotiella velutina trees.

The presence of Talbotiella velutina and other rare plant and animal species in Korup National Park shows how important this park is for the conservation of biodiversity.Four trees were found in the Besingi village forest. The chief of the village, Bila Michael Njibili, is aware of the presence of this critically endangered tree in his forest.

However, there is a great risk that the part of the forest containing the four trees will be used for slash and burn agriculture in the near future. 

Villagers in Cameroon are generally interested in the presence of rare plant species in their forests, but have a primary need to raise their families. Often farming and hunting are the only sources of income.

The seeds of Talbotiella velutina are not bankable in seed banks as they contain too much water to be stored for more than a few days.

Preserved samples of Talbotiella velutina are stored in 11 herbaria: two in Cameroon, seven in Europe and two in the USA (B, BR, G, K, MA, MO, P, SCA, WAG, US, YA).

Distribution

Cameroon

Ecology

Primary rainforest on well-drained sandy soil, at 50 to 100 m above sea level, with annual rainfall of 5,030 mm.

Conservation

Rated by the IUCN as Critically Endangered (CR D).

Hazards

None known.