Tragia zenkeri Pax

6. Tragia zenkeri Pax View in CoL ( Pax 1897: 528)

Fig. 6 B View Figure 6

Type

CAMEROON – Centre Region • Yaoundé ; Dec. 1893; Zenker & Staudt 88; lectotype ( designated here): K [ K 000425698 ] image; isolectotype: BM [ BM 000911173 ] image .

Description

Twining or scrambling perennial herb or shrub of unknown height; young and mature branches pubescent with stinging hairs up to 0.8 mm long. Stipules triangular-lanceolate, ca 4.3 × 1.2 mm, acute, pubescent with stinging hairs up to 0.8 mm long. Petioles 0.5–2.5 cm long, pubescent with stinging hair up to 0.8 mm long; distal and proximal pulvinate. Leaf blade elliptic, 4.2–8.4 × 2.3–3.8 cm, cordate at base, acuminate at apex, with acumen up to 0.8 cm, sinuate, with few tufted hairs at the teeth apex, upper surface pubescent with stinging hairs up to 0.8 mm, densely on veins, lower surface pubescent with stinging hairs up to 0.5 mm long, densely on veins; basal veins 7, secondary veins 4–5 pairs. Inflorescences bisexual, up to 2 cm; peduncle up to 1.5 cm, densely pubescent with slightly curved hairs up to 0.5–0.8 mm. Male segment up to 0.4 cm long; bracts rounded, ca 1.3 × 1.3 mm, pubescent with stinging hairs up to 0.3 mm long; without bracteoles. Female segment with 1–2 flowers; bracts distally regularly 3–4 - dentate until 1 / 3 of the length, 1.5 × 2 mm, densely pubescent, with hairs, ciliate; bracteoles oblong, 1.5 × 0.5 mm, densely pubescent, with minute hairs, ciliate. Male flower pedicel ca 1.5 mm long, pubescent with minute hairs; buds ca 1 mm in diameter; calyx lobes subrounded, 1 mm long, sparsely hairy with minute hairs; stamens 3; filaments up to 0.5 mm long; anthers 0.7 × 0.5 mm. Female flower sessile; calyx lobes 6, obovate, entire, with 1–3 subulate teeth on each side, 2.1 × 1.1 mm, densely pubescent, with hairs, ciliate; ovary 0.8 × 1.1 mm, densely hispid; styles 0.7–1 mm, connate at base, densely hairy, mainly at base. Fruits sessile, (2 –) 2.5 × 4.2 mm, densely hispid, hairs up to 0.3 mm; calyx lobes up to 4 mm long, lobulate, laminula oblanceolate, 1.5 (– 2) × 1 (– 1.5) mm, with 1–3 teeth, slightly hardened in the central part, densely pubescent, with hairs, ciliate; columella 2 mm long. Seeds 3.5 mm in diameter, dark brown with yellowish patches.

Distribution

Cameroon ( Pax 1897; Prain 1913) (Fig. 6 B View Figure 6 ), Equatorial Guinea (Fig. 6 B View Figure 6 ), Gabon ( Prain 1913) (Fig. 6 B View Figure 6 ), and possibly present in other Central African countries.

Habitat and ecology

It grows in inselbergs and other rocky areas, forest edges, and galleries at 100–758 m elevation.

Additional material examined

CAMEROON – Centre Region • Mefou Proposed National Park, Ndnan 1, eastern part of parc, track 2, through abandoned village NE of Ndangan 1 to river ; 3°37’19”N, 11°36’3”E; 710 m; 19 Mar. 2004; Cheek 11865; BR [ BR 0000016245891 ] image, K [ K 000678394 ] image GoogleMaps • Nkolbisson, 7 km W of Yaoundé ; [ 3°52’14”N, 11°27’16”E]; 700 m; 3 Mar. 1965; Leeuwenberg 5005; BR [ BR 0000016249097 ] image GoogleMaps . – North-West Region • Nwa subdivision, Lus ; [ 6°40’59.988”N, 10°58’0.012”E]; 650 m; 6 May 1980; Baeke 6; BR [ BR 0000016248601 ] image GoogleMaps • Piste Baji-Essu, 20 km NNE, Essu, village situé à 20 km au N de Wum ; [ 6°33’59”N, 10°05’12”E]; 500 m; 14 Jul. 1975; Letouzey 14037; BR [ BR 0000016244979 ] image, P [ P 00346742 ] image. – Unknown region GoogleMaps • s. loc.; s. d ..; Bagshawe 727; K [ K 000425699 ] image .

EQUATORIAL GUINEA – Bioko Sur • Malabo-Luba-Riaba, estrada kms 62–63 ; [ 3°24’06”N, 8°44’20”E]; 30 Sep. 1989; Carvalho 4121; MA [ MA-845064 ] GoogleMaps • Gran Caldeira de Luba ; [ 3°21’12”N, 8°30’47”E]; 26 Feb. 1990; Carvalho 4261; MA [ MA-874885 ] GoogleMaps • Entre el cruce de Moca y Riaba, km 1–2 ; 750 m; [ 3°25’11”N, 8°38’56”E]; 13 Feb. 1989; Fernández Casas 11576; MA [ MA-845245 ] GoogleMaps • Servicio Agronómico de Musola ; [ 3°26’16”N, 8°36’46”E]; 16 Jan. 1947; Guinea 1426; MA [ MA-204013 ] GoogleMaps • Musola S. Agromé site ; [ 3°26’16”N, 8°36’46”E]; 3 Jan. 1951; Guinea 1426 bis; MA [ MA- 02-00294522 ] GoogleMaps .

GABON – Nyanga • Moukalaba, Réserve des Monts Doudou, Sud-Ouest de la Brigade de Moukalaba, village Mourindi ; 2°34’S, 10°44’E; 100 m; 22 Mar. 2000; Sosef 926; LBV, WAG [ WAG.1339085 ] GoogleMaps . – Ogooué-Lolo • Mont Mbigou, surplombe l’ancien village de Komi ; 0°58.9’S, 11°49.9’E; 505 m; 30 Apr. 2002; Parmentier 2655; BRLU GoogleMaps . – Woleu-Ntem • Oyem, Inselberg Ossapanda ; 1°38.82’N, 11°37.79’E; 758 m; 13 Jan. 2003; Ngok Banak 1421; BRLU, LBV, WAG [ WAG.1339087 ] GoogleMaps • Minkébé National Park ; 1°23.25’N, 12°34.00’E; 635 m; 2 May 2003; Ngok Banak 1555; BRLU, LBV, MO [ MO-4496663 ], P n. v., WAG [ WAG.1339086 ] GoogleMaps • Mont Miwa, inselberg à 3 km du village de Kumassi, à 35 km d’Oyem vers Bitam ; 1°50’N, 11°38’E; 720 m; 15 Apr. 2002; Parmentier 2337 bis; BRLU GoogleMaps .

Notes

Tragia zenkeri was previously treated as a synonym of T. tenuifolia Benth. We reinstate this species here after studying the type material, and identify it as a new record for Gabon.

We have selected as the lectotype of Tragia zenkeri the specimen Zenker & Staudt 88 because it is the best-preserved preparation and includes all the morphological details for proper identification. A duplicate of this gathering was probably lost because of the bombing raid that affected the Berlin Herbarium.

After the study of material from the continent and the islands, we can confirm that T. tenuifolia is endemic to São Tomé, growing in xeric coastal formations. The copious material identified as T. tenuifolia from mainland Africa belongs to various morphologically similar species ( T. laminularis , T. mildbraediana , or T. spathulata ). Some of the Gabonese collections cited by Sosef et al. (2006) under Tragia sp. ( Ngok Banak 1421, 1555; Sosef 926) belong to T. zenkeri .

Tragia zenkeri occurs in West-central Africa, where T. mildbraediana and T. sericea are also present (see Diagnosis of T. sericea and Notes with T. mildbraediana ).