Tovomita clarkii Pipoly ex L. Marinho & Gahagen, 2016

Marinho, Lucas C., Gahagen, Benjamin & Amorim, André M., 2016, Description of Tovomita clarkii (Clusiaceae), an endemic species from Venezuela, Phytotaxa 261 (1), pp. 87-91 : 88-90

Tovomita clarkii Pipoly ex L. Marinho & Gahagen , sp. nov. ( Figs. 1–2 )

Holotype: — VENEZUELA. Territorio Federal Amazonas [= Estado Amazonas]: De partamento de Río Negro, San Carlos de Río Negro, ca. 20 km S of confluence of Río Negro and Brazo Casiquiare, 01º56’N, 67º03’W, 119 m, 27 November 1981, H. L. Clark & P. Maquirino 8291 (holotype US!, barcode 588617).

Diagnosis — Tovomita clarkii Pipoly ex L. Marinho & Gahagen (Clusiaefoliae informal group) is morphologically similar to T. weddelliana Planchon & Triana (1860: 277) by exhibiting terminal and oblanceolate leaves clustered near the branch apex, which is distinguished by exudate color (yellow vs. white in T. weddelliana ), petioles 1.6–2.2 cm long (vs. sessile to 5 mm long in T. weddelliana ), and fruit stylodia (6–7 mm long vs. sessile to 2 mm long in T. weddelliana ).

Description —Trees or shrubs up to 6 m tall, with prop roots; exudate yello w; proximal internodes 0.8–4.1(–9.3) cm long, distal internodes 0.3–1 cm long. Leaves opposite; leaf blades 9.8–11.9 × 3–3.9 cm, coriaceous, obovate to oblanceolate, base attenuate to oblique, margin entire, slightly revolute in sicco, apex rounded, sometimes slightly retuse, abaxial surface without black dots; petiole 1.6–2.2 cm long, with conspicuous transverse striations; secretory canals immersed, inconspicuous.Venation simple brochidodromous, midvein impressed adaxially, prominent abaxially, secondary veins 15–20 pairs, slightly prominent in sicco, forming angles ca. 50º with the midvein; 3.3–6.7 mm distant from each other, major secondary spacing regular; intersecondary veins 1 per intercostal area, parallel to secondaries (visible in sicco), disorderly arranged. Inflorescence a pleichasial cyme with up to 15 flowers on staminate plants, or a dichasial cyme with up to 3 flowers on pistillate plants; the central flower of dichasia without articulated pedicels; pedicels (7.1–) 11.3–12.3 mm long, bracts and bracteoles caduceus, scars visible; floral buds 6.2–7.3 × 6.3–7.1 mm, spherical, apex rounded. Staminate flowers with two outer sepals, 7–7.5 × 6.5–7.5 mm, greenish to white, oblong to orbicular, concave, fleshy, base truncate, margin entire, apex rounded; inner sepals 2, 7–7.5 × 5–6 mm, oblong, concave, fleshy to membranous, base truncate, margin entire, apex rounded; petals 4, 6–8 × 3–6 mm, oblong to orbicular, concave, fleshy to membranous, base truncate, margin entire, membranous, apex rounded; stamens ca. 25, 4.5–5.5 mm long, isodynamous; filaments dorsiventral compressed; anthers 1.5–2 mm long, as wide as filaments; pistillode ca. 1 mm long, conical, stigmas 5, elliptic. Pistillate flowers not seen. Fleshy capsules 1.1–1.6 × 1.5–1.6(–4.2) cm, young fruits ovoid, pale green when immature, pericarp splitting septifragally into 5 valves, fragments of sepals, petals and staminodes persistent; epicarp smooth; mesocarp pink to reddish; stylodia 6–7 mm long, fused half-way up. Seeds 1.3–1.5 × 0.7–0.9 cm, reniform, vascularized aril.

Specimens studied— VENEZUELA. Territorio Federal Amazonas [= Estado Amazonas]: Departamento de Río Negro, San Carlos de Río Negro , ca. 20 km S of confluence Río Negro and Brazo Casiquiare , 01º56’N, 67º03’W, 119 m elev .; average rainfall 3400–3600 mm /year, 15 May 1980 (fr.), H. L. Clark 7585 (Paratypes — INPA!, US!).

Some of the specimens labeled by J. J. Pipoly as Tovomita clarkii (see Excluded specimens), and cited by Cuello (1998) as “ Tovomita sp. F ” are different to the first specimen labeled by Pipoly as T. clarkii . The leaves of Pipoly’s specimen have rounded, or often slightly retuse, apices, and the floral buds are spherical with rounded apices. Some of the specimens Cuello (1998) listed have leaves with acute apices and strongly prominent secondary veins; the floral buds are ovoid with the apex acute. For these reasons, we believed these are distinct to T. clarkii and decided not using them as type specimens. Furthermore, we have not been able to locate the additional specimens labeled by Cuello (i.e. Liesner 8620, 8763 and Liesner & Clark 9094, from MO).

Excluded specimens— VENEZUELA. Territorio Federal Amazonas [= Estado Amazonas]: Departamento de Río Negro, middle part of the Río Baria, forest around small laja, 01º05’N, 66º25’W, 80 m elev., 29 June 1984 (bud), G. Davidse & J.S. Miller 26796 (MO!). Territorio Federal Amazonas [= Estado Amazonas]: Departamento de Río Negro, middle part of the Río Baria, inundated forest along river, 01º27’– 01º10’N, 66º32’– 66º25’W, 80 m elev., 29 June 1984 (bud), G. Davidse 27596 (MO!).

Distribution, habitat and conservation — This species is endemic to Southern Venezuela. It grows in areas close to watercourses in flooded forests, which are called igapó if they are along black-water rivers and várzea if they are along white-water rivers ( Oliveira et al. 2001). According to the IUCN (2012) criteria, and due to the low number of samples known, we have designated the species as Data Deficient (DD).

Etymology — The specific epithet honors the American botanist and ecologist Howard Lamar Clark (1941–2009), who made many collections in South America, especially in Ecuador and Venezuela. Clark was also the collector of the paratype collections of the species.

Taxonomy — The leaves of Tovomita clarkii are similar to Clusia Linnaeus(1753:509) species by their oblanceolate shape and numerous inconspicuous veins, however, the floral bud morphology is typical of Tovomita , where the outer two sepals are fused in bud or at least overlapping the bud (vs. outer two sepals small and not fused in bud). The leaves of T. clarkii are also similar to the leaves of Tovomitopsis saldanhae Engler (1888: 457) , a species distributed in the southeastern Atlantic Forest in Brazil, which can be distinguished by the organization of the floral bud and the number of carpels. Thus, T. saldanhae has small outer sepals that do not cover the bud, while in T. clarkii the outer sepals cover the bud. Flowers are 5-carpellate in Tovomita clarkii and 4-carpellate in Tovomitopsis saldanhae . For more characters see Tab. 1.

Tovomita clarkii belongs to the Clusiaefoliae informal group (= Tovomita subsect. Clusiaefoliae Vesque [1893: 189] ). Species of this group exhibit secondary and intersecondary veins with similar caliber and very close to each other; additionally, the veins are not arched, or only slightly so, near the blade margin. The new species is morphologically similar to species previously included in the T. weddelliana complex, which is distinguished by color of the exudate (yellow vs. white in the T. weddelliana complex), petioles 1.6–2.2 cm long (vs. sessile to 5 mm long in the T. weddelliana complex), and fruit stylodia (6–7 mm long vs. sessile to ca. 2 mm in the T. weddelliana complex) ( Gahagen et al. 2015). Moreover, T. clarkii has stamens and staminodes filaments compressed dorsiventrally, while the species of T. weddelliana complex have terete filaments.

Besides the species of the Tovomita weddelliana complex, T. clarkii is similar to T. calophyllophylla García-Villacorta & Hammel (2004: 132) , a species that occurs in white soil areas of Brazil and Peru ( García-Villacorta & Hammel 2004). Tovomita calophyllophylla exhibits a long, striate petiole, spherical floral buds, and can be distinguished from T. clarkii by characters of the leaf blade ( Tab. 1).

Figures

FIGURE 1. Type locality of Tovomita clarkii (black circle) in southern Venezuela.

FIGURE 2. Tovomita clarkii: A. Stem with floral buds; B. Leaf shape; C. Inflorescence; D. Detail of the stamen, showing dorsiventral compression; E. Immature fruit, showing fragments of sepals, petals and staminodes persistent (A–D based on H.L. Clark & P. Maquirino 8291; E based on H.L. Clark 7585, illustration by L.C. Marinho).