Tarenna harleyae Jongkind, 2021

Jongkind, Carel C. H., 2021, Tarenna harleyae (Rubiaceae), a new forest species from West Africa, Phytotaxa 520 (2), pp. 209-214 : 211-214

Tarenna harleyae Jongkind , sp. nov. ( Fig. 2 , 3 )

Type:— LIBERIA. Sino: ca. 50 km E of Greenville , 5°04.5’ N, 8°34.5’ W, 152 m, 11 March 2014 (fl.), C . C . H. Jongkind, D. M . Mulbah, E . Harris, J . S . Charleson & J . Forkpah 12363 (holotype BR; isotypes E, G, K, LISC, MO, P, WAG [ WAG.1577083]) .

Diagnosis:—Resembling Tarenna nitidula ( Bentham 1849: 390) Hiern (1877: 90) in the habit, the calyx pubescent outside, and the corolla glabrous outside; it differs by the corolla tube 6–8 mm long, glabrous inside (vs. 3–5 mm long, puberulous in T. nitidula ), calyx lobes 1–1.5 mm long (vs. <1 mm long), and leaf blade rather abruptly narrowing to the acuminate apex, with hairy pit domatia below (vs. blade gradually narrowing to the, often long-acuminate apex, with glabrous pit domatia below).

Description:— Shrub or small tree 1–8 m tall; main trunk to 10 cm dbh. Twigs and branches glabrous or with a few tiny appressed hairs. Stipules triangular, ca. 6 mm long, glabrous, shiny outside, pubescent inside. Leaves with petioles 4– 10 mm long, with a line of appressed, pale hairs at edges; blades narrowly obovate-elliptic, 4–18 × 1.5–5 cm, gradually narrowing to the petiole, usually rather abruptly narrowing to the acuminate apex, glabrous and glossy above, below paler and glaucous, with scattered, appressed hairs, secondary veins 7–9 on each side of midrib, with hairy pit domatia below. Inflorescence terminal, trichotomously branched, lax, wider than long, peduncle up to 2.5 cm long, branches appressed pubescent, slender hairy bracts 1–2.5 mm long. Flowers actinomorphic, 5-merous; pedicels 1–3 mm long. Hypanthium glabrous. Calyx tube ca. 0.5 mm long; lobes triangular, 1–1.5 mm long, appressed pubescent. Corolla glabrous; tube 7–8 mm long; lobes contorted to the left, linear, 9 mm long, rounded at tip. Stamens inserted just below the corolla mouth; filaments ca. 2 mm long glabrous; anthers completely exserted, ca. 8 mm long. Ovary 2-locular. Style ca. 12 mm long, exserted, middle portion pubescent; stigmatic lobes fused, glabrous. Fruit drupaceous, globose, 6–8 mm in diam., passing from green to black, smooth, glabrous except for a few hairs around the persistent calyx, with several seeds. Seeds angular, ca. 3 mm long, with a conspicuous adaxial cavity.

Additional specimens examined (paratypes): — GUINEA. Massif du Ziama , May 1945 (fl. bud), R . R .A. Schnell 2684 ( P) .

SIERRA LEONE. Kambui Forest Reserve , 13 April 1955 (fl. bud), H . D. Jordan 2036 ( K, P); Gola National Park , 1.2 km W from Malimbe camp, 23 October 2013 (imm. fr.), J . Momoh, X. M . van der Burgt, L . Lopez Poveda, B . Saradugu, M . Swaray, A . Jusu & M . P . Sesay 34 ( K, WAG); Gola National Park , central block, 20 October 2013 (fr.), M . P . Sesay, X. M . van der Burgt, B . Saradugu, L . Lopez Poveda, M . Swaray, A . Jusu & J . Momoh 94 ( K, P) .

LIBERIA. Massif de Kitoma , (fl. bud), J .- G . Adam 16592 ( P); Duo , 11 March 1948 (fl.), J . T . Baldwin 11334 ( K); Dukwia River , 19 February 1929 (fl.), G . P . Cooper 206 ( K); Ganta , 17 May 1939 (fl.), W . J . Harley 1180 ( K, WAG); Gola Forest , 2 December 2005 (fl. bud), C . C .H. Jongkind, A . K . Daniels, J . Konie & M . G . Gorpudolo 7086 ( WAG); Sapo National Park , close to Sinoe River, 7 March 2009 (fl. bud), C . C .H. Jongkind, D. Bilivogui & D. Dorbor 8859 ( BR, FHO, K, MO, WAG); north of Sapo National Park , 10 September 2013 (fl.bud), C . C .H. Jongkind, L .- A . de Wet & G . Sambolah 12222 ( BR); ca. 50 km east of Greenville , 10 March 2014 (fl.), C . C .H. Jongkind, D. M . Mulbah, E . Harris, J . S . Charleson & J . Forkpah 12346 ( BR); ca. 40 km north-east of Robertsport , 18 June 2014 (fr.), C . C .H. Jongkind & G . Sambolah 12694 ( BR, P); east of Jalay’s Town , 31 January 2016 (fl. bud), C . C .H. Jongkind & G . Sambolah 12895 ( BR); east of Pelloken village , 5 February 2016 (fl. bud), C . C .H. Jongkind & G . Sambolah 12992 ( BR); near Greenville - Zwedru road, 10 February 2016 (fl.bud), C . C .H. Jongkind & G . Sambolah 13061 ( BR); 28.9 km N of Tapeta , 18 February 1961 (fl. bud), A . G . Voorhoeve 184 ( BR, WAG); New road from Zwedru to Cape Palmas , near Kanweake, 29 March 1962 (fl.), J . J . de Wilde & A . G . Voorhoeve 3704 ( BR, P, WAG) .

IVORY COAST: Road Sassandra-Lakota, near Lagako, 7 May 1975 (imm. fr.), H . J . Beentje 29 ( BR, MO, WAG); 2 km NE of Basobli , 10 September 1975 (fr.), H . J . Beentje 957 ( WAG); km 56 road Sassandra-Gagnoa , 30 October 1968 (fr.), F . J . Breteler 5850 ( BR, K, WAG); 61 km N of Sassandra, W of Niapidou , 19 February 1959 (fl. bud), A . J .M. Leeuwenberg 2762 ( BR, WAG) .

Distribution and habitat: —South-East Sierra Leone, South-East Guinea, Liberia and South-West Ivory Coast; in undergrowth of tropical lowland forest.

Eponimy:—The species is named after Winifred Harley who studied Liberian plants for many years and collected this new species near Ganta, Liberia, where she lived.

Preliminary Conservation Status:—The estimated extent of occurrence (EOO) of this species is> 90,000 km ², which greatly exceeds the values needed for a threatened category under criterion B. The species is not rare and is known from Sapo National Park and Gola National Park, and most likely to occur in other protected areas as well. A substantial part of the herbarium specimens was collected relatively recently, and most of its original populations are still extant. Therefore, T. harleyae is provisionally assessed here as Least Concern (LC) according to the IUCN Red List Categories and Criteria ( IUCN, 2012).

Note: —The height of fertile plants of T. harleyae , as noted on the labels, is very variable, it looks like this species can start flowering when still relatively small. A few flowering specimens, cited here under the new species, were mentioned already by Degreef (2006: 106) as being somewhat different from most other T. nitidula plants.

Tarenna nitidula (Bentham) Hiern (1877: 90) .

Basionym: Stylocoryne nitidula Bentham (1849: 390) .

Type : SIERRA LEONE. s.l., s.d. [1841] (fr.), J. R. T. Vogel 147 (first-step lectotype designated by Degreef (2006: 104); second-step lectotype K [barcode K000411773 ], here designated) .

Notes: Bentham described Stylocoryne nitidula Bentham (1849: 390) and cited two gatherings from Sierra Leone: 1) Vogel s.n., 2) Whitfield s.n., and he did not state in which herbarium they are deposited. Degreef (2006: 104) cited J. R. T. Vogel 147 at K as the lectotype of S. nitidula . However, there are two specimens of Vogel 147 at K, with barcodes K 000411773 and K 000411775. The specimen with barcode K 000411773 has the label “147 S. Leone, Stylocoryne nitidula , Niger Expedition, Vogel”; this specimen is here designated the second-step lectotype.

Diagnostic characters: Calyx lobes 1–1.5 mm long. Corolla tube 3–5 mm long, throat pubescent. Most leaf blades gradually narrowing to an often long-acuminate apex, glabrous below with a crackled surface (dry) due to impressed tertiary veins; domatia, when present, glabrous.

Distribution and habitat: —Distributed from Guinea-Bissau to Ivory Coast; growing in forest undergrowth and thickets, often on slopes.

Figures

FIGURE 2. Tarenna harleyae. A. Branch with flowers. B. Stipule. C. Domatia. D. Flower. E. Flower cross section. F. Infructescence. G. Fruit opened. H. Seeds. Tarenna nitidula. I. Flower. J. Flower cross section. A-H: C.C.H. Jongkind et al. 12363 (BR); I-J: X.M. van der Burgt et al. 1146 (WAG). Drawn by Hans de Vries.

FIGURE 3. Distribution map of Tarenna harleyae.