Oldenlandia violacea K. Schum., Pflanzenw. Ost-Afrikas C, 1895

Zhou, Ya-Dong, Amenu, Sara Getachew, Mwachala, Geoffrey, Hu, Guang-Wan & Wang, Qing-Feng, 2021, Reinstatement of the independent specific status of Oldenlandia violacea (Rubiaceae) from the synonymy of O. monanthos, Phytotaxa 507 (4), pp. 293-300 : 296-298

Oldenlandia violacea K. Schum., Pflanzenw. Ost-Afrikas C : 374. 1895. Fig. 2A–F .

Type:— Tanzania, Kilimanjaro, Marangu , 2300 m, 15 Sept. 1893, Volkens 848 [holotype: B (not seen); isotypes: BM (not seen), E (E00193621!), K (K000414323!)] .

Perennial glabrous prostrate herb, up to 60 cm long, rooting at the nodes. Leaves opposite; blades ( Fig. 2B & C ) lanceolate, elliptic-oblong to elliptic, 5–35 × 2–12 mm, acute at the apex, cuneate to rounded at the base; petiole 1.2–3 mm long; stipule-sheath ( Fig. 2D ) 0.7–3 mm long, lobe triangular, 4–10-setose. Flowers ( Fig. 2E ) solitary, paired or several in fascicles, 4-merous, heterostylous; pedicels up to 2.6 cm long. Calyx-tube ( Fig. 2E ) campanulate, 2–4 mm long, glabrous; lobes ovate-triangular, 1–3 mm long. Corolla ( Fig. 2E ) white; tube 2–4 mm long, densely hairy at the throat; lobes ovate, 2–4 mm long. Capsules ( Fig. 2F ) obconic-campanulate, 3–5 mm long, 2–4 mm wide, glabrous.

Distribution:— Ethiopia, Kenya and Tanzania.

Habitat:—Upland forest floor, edge of the forest, streamside, woodland; 1550–2750 m.

Additional specimens examined:— ETHIOPIA. Tigre: ca. 17 km. S. of Maichew, De Wilde 6933 (WAG); Harerge: on the road from Alemaya village to Asbe-Tafari, Westphal & Westphal-Stevels 1254 (WAG). KENYA. Bomet: Western Mau Forest Reserve, Geesteranus 5766 (K). Elgeyo-Marakwet: Kibukuimet, SAJIT 007055 (HIB). Kajiado: Ngong Hills, Lind et al. 5748 (EA); Chyulu Hills, Luke et al. 11567 (EA). Kericho: Sambret, Kerfoot 2781 (EA). Nakuru: Eburru Forest, Luke et al. 8935 (EA). Narok: Ndunyangerro, Glover et al. 1682 (EA). Nyandarua: Edge of Kinangop Plateau, Kuchar 12337 (EA). Trans Nzoia: Mount Elgon, Beentje 1939 (EA). Uasin Gishu: Tinderet Forest Reserve, Geesteranus 5397 (K). West Pokot: Cherangani Hills, SAJIT Z0075 (HIB). TANZANIA. Monduli: Monduli Forest Reserve, Simon et al. 735 (MO); Arumeru: Mount Meru, Gereau & Abdallah 1715 (MO).

Figures

FIGURE 2. Oldenlandia violacea. A, Habitat; B & C, Leaves; D, Stipules; E, Flowers; F, Fruits. O. monanthos. G, Habitat; H, Stipules; I, Plant with flower and young fruits; J, Longitudinal section of the flower, showing stamens and style. All the scale bars are 10 mm. Photo by SWW (A, E), GWH (B–D, F, J) and YDZ (G–I).