Dracaena waltersiae Damen, 2018

Damen, T. H. J., Burg, W. J. van der, Wiland-Szymańska, J. & Sosef, M. S. M., 2018, Taxonomic novelties in African Dracaena (Dracaenaceae), Blumea 63 (1), pp. 31-53 : 47-48

24. Dracaena waltersiae Damen , sp. nov. — Plate 9, 10; Map 23

Dracaena waltersiae is similar to D. laxissima , but it differs from that species in having petioles of only 2–3 mm long, a racemose inflorescence, flowers of 27–28 mm long with pedicel of only 6–9 mm. In D. laxissima the petiole is 5–12 mm, the inflorescence is paniculate, flowers are 16–20 mm long and have a slender pedicel of 11–21 mm. — Type: Walters & Niangadouma 1271 (holo MO; iso LBV (LBV0002600), WAG (WAG0102272)), Gabon, Haut-Ogooué Prov., Plateaux Batéké National Park,Mpassa River drainage, Kalahari Sands, Projet Protection des Gorilles, ‘Okeli Forest’ trail M, S2°08' E14°04', alt. 420 m, 3 Mar. 2003.

Etymology. Dracaena waltersiae honours Mrs Gretchen Walters who has collected the type and brought the plant to my attention. With her work, notably that on the Plateaux Batéké,she has made a substantial contribution to our knowledge of the flora of Gabon.

Lianescent shrub or tree of up to 10 m high; bark grey and slightly longitudinally fissured, without resin; branches with internodes of (0.4–)1.5–3(–4) cm. Leaves evenly distributed along the branches, distichously arranged; pseudopetiole c. 2–3 mm long, distinctly darker than the lamina, scariously winged, its base widened and clasping the stem for 0.5–0.7 times its circumference; lamina subfalcate, elliptic to oblanceolate, up to 14 by 3 cm, apex acute to acuminate, mucro 1 mm long, base attenuate, thinly coriaceous, midrib impressed above, prominent beneath, secondary nerves not evident above, prominent beneath. Inflorescence terminal or subaxillary, racemose, to c. 30 cm long, occasionally with a few branches; peduncle smooth, fluorescent orange, with fascicles of up to c. 4 flowers, each fascicle subtended by a small triangular, scarious, caducous, brown bract, of up to 4 mm long. Flower:

Map 23 Distribution of Dracaena waltersiae Damen. Plate 9 Dracaena waltersiae Damen , scan of herbarium sheet showing infructescence and leaf arrangement; Walters 1072.

pedicel 6–9 mm long, articulating at c. 1 mm from the apex, green-white, purplish near the apex; floral bracts inconspicuous, triangular, up to c. 1 mm long, scarious; perianth c. 27–28 mm long, with a pleasant odour, lobes 16–17 by 1.5 mm; stamens inserted near the throat, up to 4 mm shorter than the lobes, filaments filiform, anthers c. 2 by 1 mm; style exserted for up to 1 mm, stigma capitate, c. 0.9 mm diam. Fruits 1–3-seeded, depressed globose, c. 16 by 20 mm (in herbarium), red-brown; receptacle 3 by 2 mm. Seeds not seen.

Distribution — Gabon, Central African Republic, Republic of the Congo.

Ecology — Edge savanna with forest, flooded forest, gallery forest, dry forest on white sand, Kalahari Sands, 50 m from edge of forest. Palisota and Memecylon in closed understory; at 400–620 m altitude. Flowering in March and April.

Other specimens examined. CENTRAL AFRICAN REPUBLIC, Haut-Mbomou, region d’Obo, PK 57, route de Zémio, c. N5°20' E26°27', 31 Dec. 1963, Descoings, BM 12233 ( MPU, P); ibid., 31 Dec. 1963, Descoings, BM 12238 ( P) . – GABON, Haut-Ogooué, Parc National des Plateaux Batéké,forêt proche du Bai Jobo (1.5 km), S2°13' E13°50', 6 June 2005, Niangadouma, R 536 ( MO); Batéké Plateau, Mpassa River watershed , station of the Projet de Protection des Gorilles , S2°08' E14°04',alt. 400 m, 4 Dec. 2001, Walters, GM 1072 ( MO, WAG); Plateaux Batéké National Park , Mpassa River drainage, S2°07.3' E14°04.1', alt. 460 m, 27 Feb. 2003, Walters, GM 1138 ( MO, WAG); ibid., S2°07.3' E14°04.1', alt. 460 m, 27 Feb. 2003, Walters, GM 1147 ( LBV, MO, WAG) . – REPUBLIC OF THE CONGO, Pool, Pays Batéké, de Brazzaville à St. Joseph du Nkoué [= Kibouendé], S4°09' E14°54', 29 July 1912, Chevalier, AJB 27333 ( P); environs de Brazzaville, c. S4°15' E15°17', 10 Feb. 1971, Makany, L 1686 ( P) .