Uvariodendron usambarense R.E.Fr., Acta Horti Berg. 10: 65 (1930)

Dagallier, Leo-Paul M. J., Mbago, Frank M., Couderc, Marie, Gaudeul, Myriam, Grall, Aurelie, Loup, Caroline, Wieringa, Jan J., Sonke, Bonaventure & Couvreur, Thomas L. P., 2023, Phylogenomic inference of the African tribe Monodoreae (Annonaceae) and taxonomic revision of Dennettia, Uvariodendron and Uvariopsis, PhytoKeys 233, pp. 1-200 : 1

Uvariodendron usambarense R.E.Fr., Acta Horti Berg. 10: 65 (1930)

Figs 46 , 47

Type.

Tanzania - Tanga • G. Scheffler 226 (lectotype, here designated: EA! (EA000002471); isolectotypes: A! (A00039714), BM! (BM000554074), E! (E00704857, E00704858), EA! (EA000002470), P! (P00363394); B sheet lost or destroyed), E Usambara Mts. , Derema; 5°05'S, 38°38'E; 26 Mar. 1900 .

Description.

Tree 8-30 m tall, D.B.H. 17-30 cm; young branches pubescent to glabrous, old branches glabrous; the bark is dark on young individuals, peels on old individuals letting appear a pinkish-grey layer. Petiole 5-15 mm long, 1.5-6 mm wide, pubescent to glabrous. Leaf lamina 283-564 mm long, 79-180 mm wide, length:width ratio 2.4-3.9, obovate to oblong to elliptic, coriaceous, base rounded to subcordate, apex acuminate, acumen 5-18 mm long; surface above glabrous, surface below sparsely pubescent to glabrous when young, glabrous when old; midrib impressed above, raised below, glabrous above, sparsely pubescent to glabrous below; secondary veins 18-30 pairs, weakly brochidodromous, impressed above, raised below; tertiary veins reticulate. Inflorescences borne on trunk and old branches, composed of 1 flower. Flower pedicel unknown. Flowers bisexual, buds ovoid, sessile, ca. 10 mm high, ca. 6 mm in diameter, pubescent. Only old rotten flower seen. Bracts unknown, 1 to 3 bracts scars observed on fruiting pedicel. Sepals 3, length, shape and indumentum unknown. Outer petals 3, ca. 20-30 (?) mm long, ca. 10-20 (?) mm wide (measures taken on old and rotten flower), length:width ratio ovate, greenish yellow to brown with dark red streak from base up to 50% of the petal length inside. Inner petals 3, length, shape, indumentum and color unknown. Stamens unknown. Carpels unknown. Fruiting pedicel 12-22 mm long, 4-8 mm in diameter, pubescent to glabrous. Monocarps 1 to 17, 50-89 mm long, 18-27 mm wide, length:width ratio 1.8-3.6, cylindrical, pubescent to sparsely pubescent, pale yellowish green (unripe?); stipe 1-5 mm long, 6-10 mm wide, pubescent to glabrate. Seeds 16-25 per monocarp, biseriate, 20 to 25 mm long, 12-14 mm wide.

Distribution.

Endemic to Somalia-Masai Region. Tanzania: Usambaras mountains and Udzungwa mountains.

Habitat and ecology.

Submontane to montane rain forest. Altitude: 961-1000 m a.s.l.

Phenology.

Flowers collected in August and November. Fruits collected from March to November.

Vernacular names.

Tanzania: ‘Mkenene’ in Kinguru (Greenway 8628, Swynnerton 1110), ‘Mkomboa’ in Kisamba (Mwangoka 1593), ‘Ntambileni’ in Kinguru (Mwangoka 3272).

Notes.

This species resembles Ud. calophyllum , Ud. connivens , Ud. fuscum and Ud. molundense in having great obovate to elliptic to oblong leaves (28-57 cm), but can be differentiated in having rounded to subcordate leaf bases (vs. acute to rounded), and a dark bark when young, peeling off when old, letting appear a pinkish-grey layer.

Preliminary conservation status.

A previous assessment, which needs updating, listed this species as Endangered EN under criteria B1ab(iii) (Eastern Arc Mountains & Coastal Forests CEPF Plant Assessment Project 2009d). Here the EOO is estimated at 13,513 km2 and AOO at 44 km2. It is known from 14 occurrences in Tanzania, situated in East Usambara Mountains, Uluguru Mountains and Udzungwa Mountains. Following IUCN criterion B, it would be assigned a preliminary conservation status of Endangered EN based solely on AOO, but no other subcriteria is met (b or c). Most of these occurrences are situated in protected areas such as the Udzungwa Mountains National Park and the Amani Nature Reserve. The future of this species relies on the future of these protected areas. It is thus assigned a preliminary updated conservation status of Near Threatened NT.

Additional specimens examined.

Tanzania - Morogoro • A.R. Marshall 1100 (K), Msolwa - PSP9. Udzungwa National Park. udzungwa Mountains ; 7°42'30.36'S, 36°53'06.73'E; alt. 1124 m; 05 Aug. 2007 • B.J. Harris 4610 (DSM, K); Morogoro Rural District, Uluguru Mtns. near Kinole ; 6°54'S, 37°47'E; alt. 900 m; 30 Apr. 1970 • C.F.M. Swynnerton 1110 (K); Morogoro Rural District, S Nguru Forest Reserve, Manyangu Forest , Liwale River ; 6°07'S, 37°34'E; Feb. 1920 • M.A. Mwangoka 3272 (MA, MO); Morogoro Rural District, Nguru Mountains, Nguru South Forest Reserve , along valley between Mafuta and Ubili villages; 6°04'34'S, 37°33'33'E; alt. 555 m; 12 Aug. 2004 • P.J. Greenway 8628 (BM, K); Morogoro Rural District, S Nguru Forest Reserve, Manyangu Forest , Liwale River ; 6°07'S, 37°34'E; alt. 760 m; 21 Aug. 1951 • W.R.Q. Luke 8737 (EA, K, NHT), Pt 303, Camp 244; 7°43'S, 36°54'E; alt. 900 m; 06 Jun. 2002 • Y.S. Abeid 2666 (EA, MO); Mvomero District, Kanga Forest Reserve, Submontane Forest , Work Unit 3, Base Camp ; 5°55'S, 37°42'28'E; alt. 1140 m; 23 Mar. 2006 - Tanga • A.L. Borhidi 82031 (DSM, K); Lushoto District, Amani-Sigi Forest Reserve at the Sigi headwaters S of Amani near Kwamkoro sawmills; 5°10'S, 38°36'E; alt. 900 m; 19 Feb. 1982 • F.M. Mbago 3707 (DSM); Lushoto District, Amani, above Kisiwani village ; 5°06'53.38'S, 38°39'16.51'E; alt. 961 m; 16 Oct. 2015 • I. Rajabu Hizza 185 (MO); Muheza District, T 3. Amani Nature Reserve, phenology transect P-T 2, Kisiwani ; 5°06'S, 38°40'E; alt. 400 m; 17 Nov. 1998 • J.C. Lovett 816 (DSM, K, MO); Muheza District, East Usambara mountains, Kwamkoro Forest Reserve. Area currently being logged by Sikh sawmills; 5°10'S, 38°35'E; alt. 950 m; 11 Jun. 1986 • L.-P.M.J. Dagallier 34 (BR, DSM, K, MO, MPU, P, WAG); Muheza District, Amani Nature Reserve ; 5°06'31.38'S, 38°39'45.44'E; alt. 687 m; 12 Nov. 2019 • L.B. Mwasumbi 112429 (DSM), Kwamkoro N. R; 5°10'S, 38°36'E; 08 Nov. 1998 • M.A. Mwangoka 1593 (MO); Muheza District, Kwezitu public forest along path to peak between Mkalamo and Gonja Subvillages; 4°59'17'S, 38°40'12'E; alt. 825 m; 04 Aug. 2000 • T.L.P. Couvreur 20 (DSM, MO, WAG); Muheza District, c. 1 km straight up from Kisiwani village (just before Amani Nature Reserve ); 5°05'55.2'S, 38°39'40.2"E; alt. 1000 m; 11 Nov. 2006 .

Figures

Figure 46. Uvariodendron usambarense R. E. Fr. A habit B branch with leaves, upper side C branch with leaves, lower side D trunk E dried fruit, top view. A, D specimen not collected B, C Dagallier 34 E Lovett 816. Photos Leo-Paul Dagallier.

Figure 47. Distribution map of Uvariodendron usambarense. Shades of grey represent elevation, from white (sea level) to darker grey (higher elevation). The inset shows the extent of the map over Africa.