Moutabea gentryi T. Wendt, Lundellia

Silveira, João Barros Da & Secco, Ricardo De S., 2018, Taxonomic studiesin Moutabea (Polygalaceae) in Brazil, Phytotaxa 365 (3), pp. 225-244 : 238

7. Moutabea gentryi T. Wendt, Lundellia 3: 6–12. 2000. ( Fig. 5 a–f )

TYPE:— PANAMA. Prov. Panamá: Pacific slope of the Cordillera de San Blas, headwaters of the Piria River (Piriati), 28 February 1992 (fl.), H. Herrera, J. Mojica & J. Morris 1151 (holotype: TEX; isotypes:CR, MEXU, MO!, PMA) .

Liana, shrub or small tree. Bark rough, epidermis glabrous, brown to blackened. Leaf blades 13 ‒ 30.3 × 5 ‒ 11 cm, brown, coriaceous, narrow-elliptic, oblanceolate to obovate, glabrous, apex acuminate to acute, base cuneate, margin thin, punctations prominent on both surfaces (most evident adaxially), midrib flat, secondary veins prominulous adaxially, prominent abaxially; petiole 0.8 ‒ 1.3 cm long, glabrous. Racemes with rachis generally a monad, glabrous to glabrescent, 2.2 ‒ 2.5 cm long; flowers 1.5 ‒ 1.7 cm long, pedicels 1 ‒ 1.5 mm long, sepal lobes 4.5 ‒ 7 mm long, 1.5 ‒ 3 mm wide, glabrous to glabrescent on both surfaces, tips 5 ‒ 7 mm long, 1.9 ‒ 3 mm wide, staminal sheath with hood glabrescent to pubescent on dorsum, group of 4 anthers ca. 1.2 mm long, ovary 0.5 ‒ 1 mm long, 0.7 ‒ 0.9 mm diam., 5- lobed, style 8 ‒ 10 mm long, stigma capitate. Fruit surface reticulate, blackened when mature, pericarp ca. 1.8 mm thick, appearing farinaceous in cross-section; seeds 1.4 ‒ 1.8 cm, velutinous, raphe prominent, rigid.

Notes:—This species resembles M. arianiae and M. victoriana by its coriaceous leaves, with abaxially prominent secondary veins, and velutinous seeds. However, it is easily distinguished by the prominent punctations on the leaf blade, fruits with a reticulate surface and thick pericarp (1.8 mm), and prominent, rigid raphes (vs. prominent punctuation absent on the leaf blade, fruits with a smooth surface and pericarp ca. 1 mm thick, and imperceptible raphe in M. arianiae ; prominent punctuation absent on the leaf blade, fruits with a discreetly punctate surface and pericarp ca. 4 mm thick, and imperceptible raphe in M. victoriana ). It also differs from M. arianiae by the glabrous juvenile branches, petioles, abaxial surfaces of the leaves, and inflorescences. Moutabea chodatiana also has prominent punctations on its leaf blades, but unlike M. gentry it has thickened leaf margins, a fruit with a thin pericarp and glabrous seeds with raphe into depression (imperceptible raphe).

Wendt (2000) considered M. aculeata the closest species to M. gentryi . Perhaps this was because it was not known that M. arianae and M. victoriana also have leaves with prominent secondary veins, fruits with a thick pericarp and velutinous seed. Moutabea guianensis is another species that shares similarities with M. gentryi , especially the velutinous seeds with a prominent raphe.

Eriksen et al. (2000) noted a possible new species of Moutabea from northwestern Ecuador ( Moutabea sp. , Gentry &Josse 72790, QCNE) that has oblanceolate leaves with slightly elevated lateral veins on adaxial surface. These characters are also found in M. gentryi .

Aymard et al. (2004) recorded Moutabea sp. A (Liesner & González 5969; Boom & Martin 10478, Stergios & Velasco 14270, Steyermark 87617, and Peréz & Sosa 338) as a possible new species from Venezuela (Delta Amacuro and Bolívar States) and Brazil (Amazonas State). However, the characteristics mentioned by these authors are similar to those found in M. gentry (i.e., leaves with secondary veins evident on the upper side, the midrib flat, and short petiole). Furthermore, the presence of both species in the same region suggests the possibility that these collections represent a single species. A more detailed analysis of the collections, including fertile structures, should elucidate this better, because M. gentryi is easily recognized by its mature leaves that are covered with prominent punctations.

Distribution and habitat: —Occurs in Panama (Wendt 2000), and as new record in Brazil ( Fig. 6 ). In Brazil it is found in the states of Amazonas and Rondônia. Collected in upland forest, forest edges and campinarana forest.

Conservation status:— Moutabea gentry is not endemic to Brazil and its extent of occurrence in the country (EOO=18,575 Km 2) includes only the states of Amazonas and Rondônia. The species has a small area of occupancy (AOO= 16 km 2) and has only been collected in four localities in the region, which are not in protected areas. Due to its restricted distribution, this species falls within the Vulnerable (VU) category based on IUCN (2017) criteria.

Specimens examined: — BRAZIL. Amazonas: Borba, 9 November 1935, A. Ducke (MG, RB); Humaitá, platô entre Rio Livramento e Rio Ipixuna, 7 November 1934 (str.), B. A. Krukoff 7106 (NY, RB); Estrada Manaus-Porto Velho, 22 April 1976 (fr.), O. P. Monteiro & J. Ramos 884 (INPA); Estrada Manaus-Porto Velho km 245, 13 March 1974 (str.), G. T. Prance et al. s. n. (INPA, NY); Humaitá, Platô entre Rio Livramento e Rio Ipixuna, 7 November 1934 (str.), B. A. Krukoff 7056 (NY, RB). Rondônia: Porto Velho, mata do km. 8 da estrada de rodagem, 21 November 1949 (fl.), N. T. Silva 362 (IAN).

Figures

FIGURE 5. Moutabea gentryi T. Wendt. a. Branch. b. Adaxial face of the leaf with punctations prominent and veins prominent. c. Flower. d. Adnation between staminal sheath and external petal (hood medium). e. Dehydrated, blackened and broken fruit showing the thick pericarp. f.Pubescent seed with prominent and rigid raphe. (a–b, e–f from O.P. Monteiro & J. Ramos 884; c–d from N. T. Silva 362). Moutabea guianensis Aubl. g. Branch with inflorescences. h. Flower. i. Adnation between staminal sheath and external petal (hood short). j. Dehydrated and blackened fruit (surface reticulate). k. Dehydrated fruit in cross-section showing 5 locules with one seed per locule. l. Pericarp in cross-section showing the farinaceous appearance. m. Seed velutinous with raphe prominent. (g–m from Silveira s.n.). Moutabea victoriana Silveira & Secco. n. Branch. o. Flower. p. Adnation between staminal sheath and external petal (hood medium). q. Fruit. r. Dehydrated fruit in cross-section showing the thick pericarp. s.Velutinous seed with imperceptible raphe. (a from M. A. Freitas et al. 428; o–p from A. Vicentini 1007; q–s from L. H. P. Martins et al.89).

FIGURE 6. Geographical distribution of three species of Moutabea in Brazil: M. gentry, M. guianensis, and M. victoriana.