Erythroxylum niquelandense M.J. Silva & Loiola, 2021

Silva, Marcos José Da & Loiola, Maria Iracema Bezerra, 2021, A new species of Erythroxylum (Erythoxylaceae) from the seasonal dry forests of the state of Goiás, Brazil, Phytotaxa 480 (3), pp. 269-276 : 270-274

Erythroxylum niquelandense M.J. Silva & Loiola , sp. nov. ( Figs. 1–2 ).

Type:— BRAZIL. Goiás: Niquelândia, Reserva Particular de Desenvolvimento Sustentável Legado Verdes do Cerrado, Núcleo Engenho, Área Capão do Bandeira , cerca de 800 metros do seu início a direita da estrada em direção ao Mirante , aproximadamente 200 metros para dentro, 14º36’47”S, 48º29”15 W, 652 m, 29 June 2019 (fl, fr) , M. J. Silva & A. A . Alonso 9645 (holotype UFG!; isotypes: F!, NY! UB!) .

Diagnosis:—Subshrub or shrub to 1.8 m tall; leaves large, elliptic or oblong-elliptic with 12–16 secondary per side; stipules chartaceous, 3-setulose with 9 or 10 lateral nerves per side, setae 1.7–2.6 mm long, margin irregularly denticulate and apex obtuse; cataphylls different from the stipules in size with spinules 2–2.1 mm; fascicles with 10-15 flowers, buds obovoid, and bracteoles oval, scarious with margin slightly erose. This species is similar to E. citrifolium and E daphnites , but differs mainly by characters related to the habit, height, stipules, bracteoles, leaves, numbers of flowers per fascicle, and fruits.

Description:—Subshrubs or shrubs 0.75–1.8 m tall. Branchlets 3–5 mm diam., cinereous and slightly fissured longitudinally at maturity, greenish, reddish or brownish when young, lenticels elongated, discrete, cream colored; internodes 1.6–2.5 cm long. Cataphylls 7–7.3 × 4.5–4.6 mm, tardily caducous, laxly distributed along old branches, glabrous, brownish, paleaceous, spinules 2–2.1 mm long, brownish. Foliar stipules 7–8.6 × 4.9–5 mm, triangular, tardily caducous, appressed to branches, apex obtuse, striated with 9 or 10 nerves per side, conspicuously 3-setulose, the 2 lateral setae ca. 2.6 mm long, the medial setae ca. 1.7 mm long, keels conspicuously subulate, margin sparsely and irregularly denticulate. Leaves persistent or tardily caducous, alternate distichous; petiole 5.2–6 mm long, cylindrical, slightly canaliculate adaxially and transversely striated, glabrous; leaf blades 14–23.5 × 4.5–6 cm, chartaceous, concolorous, glabrous, base cuneate, apex acuminate; venation camptodromous-brochidodromous, midrib canaliculate adaxially, conspicuously prominent abaxially; secondary veins 12–16 per side, curved, impressed adaxially, discreetly prominent abaxially, tertiary veins reticulate, inconspicuous. Fascicles with 10–15 flowers, in axils of leaves or cataphylls; bracteoles 2, 0.6–0.9 mm long, 1-setulose, keel slightly subulate, scarious, cymbiform, oval, margin slightly erose, glabrous; flower buds 4.9–5 × 1.9–2 mm long, obovoid, glabrous; flowers 5–5.8 mm long, pedicel 2.9–3 mm, glabrous, 5-angled; calyx 1.1–1.2 × 1.3–1.4 mm, greenish, lobes 0.9–1 × 0.6–0.7 mm, triangular or oval-triangular, margin entire, apex acute, glabrous on both surfaces; petals 2.9–3 × 1.1–1.2 mm, elliptic or oblong-elliptic, slightly concave, apex obtuse, margin entire, white spotted greenish in the central portion; appendages ligulate, 0.9–1 mm long, 4-lobed, anterior auricles 2, 0.35–0.4 mm long, posterior auricles 2, 0.5–0.6 mm long, margin entire, discreetly undulate, central appendage developed, thickened; staminal cup 0.9–1× 1.1–1.2 mm, smaller than calyx and ovary, the margin 10-denticulate. Brevistylous flowers: stamens 2.4–2.5 mm long, cream-yellowish, anthers 0.4–0.5 mm long, oblong, light yellowish; styles 1.3–1.4 mm long, free, stigmas 0.1–0.2 mm long, depressed-capitate. Longistylous flowers: antesepalous stamens 1.9–2 mm, antepetalous stamens 2.4–2.5 mm, anthers 0.5–0.6 mm long, oblong; styles 1.4–1.5 mm, free, stigmas 0.1–0.2 mm long, depressed-capitate; ovary 1.1–1.2 mm, ellipsoid. Drupe 5–8 × 5–5.1 mm, globose, ovoid or oblong, smooth, orange or scarlet red when mature.

Additional specimens examined (paratypes):— BRAZIL. Goiás: Niquelândia, Reserva Particular de Desenvolvimento Sustentável Legado Verdes do Cerrado, Núcleo Engenho , Área Capão do Bandeira , cerca de 800 metros do seu início do a direita da estrada em direção ao Mirante , aproximadamente 200 metros para dentro, 14º36’47”S, 48º29”15 W, 652 m, 29 June 2019 (fl), M. J. Silva & A. A. Alonso 9646 ( UFG), 9647 ( UFG), 9648 ( UFG), 9649 ( UFG); ib., 14º37’30.8”S, 48º29” 42.12W, 647 m, 20 February 2020 (fl, fr), M . J . Silva, BR . Pereira & I . S . Santos 10824 ( UFG), 10825 ( UFG); ib., 4º37’30.7”S, 48º29’42.1”W, 646 m, 20 February 2020 (fl), M . J . Silva, BR . Pereira & I . S . Santos 10826 ( UFG); Área do Córrego da Sociedade , ca. de 10 metros a partir do Córrego, 14º38’34”S, 48º28’41”W, 634 m, 28 October 2020 (fr), M . J . Silva, A . A . Alonso & F . D. Santos 11113 ( UFG); ib., ca. 40 metros antes de chegar ao Córrego Sociedade, sentido Mirante, lado esquerdo da estrada, borda da vegetação, 14º38’34”S, 48º28’40”W, 654 m, 28 October 2020 (fr), M . J . Silva, A . A . Alonso & F . D. Santos 11118 ( UFG); ib., ca. 5 metros antes de chegar ao Córrego Sociedade, sentido Mirante, lado esquerdo da estrada, borda da vegetação, 14º38’34”S, 48º28’4”W, 654 m, 28 October 2020 (fr), M . J . Silva, A . A . Alonso & F . D. Santos 11121 ( UFG); ib., ca. 60 metros a partir do Córrego Sociedade, sentido Mirante, lado esquerdo da estrada, borda da vegetação, 14º36’31”S, 48º28’43”W, 623 m, 28 October 2020 (fr), M . J . Silva, A . A . Alonso & F . D. Santos 11129 ( UFG), 11130 ( UFG) .

Distribution, habitat and phenology:—This species is currently known from the seasonal forests in municipality of Niquelândia, in the northern portion of the state of Goiás ( Fig. 3 ). It grows near streams on clayey soils rich in litter, between altitudes of 634 and 654 m.

Etymology:—Specific epithet refers to the municipality of Niquelândia, located in the northern portion of the state of Goiás, where the species was first collected.

Preliminary Conservation Status:—The species extent of occurrence was calculated as 0.701 km 2, which lead us to classify it, according to the IUCN criteria, as Critically Endangered ( CR). However, this species grows in a common type of vegetation in the state of Goiás. With additional exploration and systematic collections in this area, its distribution may expand, so we chose to consider its conservation status as Data Deficient ( DD). It should also be noted that the species was collected in a permanent unit for the protection of biodiversity forming populations with about 30 individuals .

Morphological relationships and systematic position:— Erythoxylum niquelandense is assigned to Erythroxylum sect. Rhabdophyllum O. E. Schulz (1907: 29) based on evidently striated stipules and cataphylls with generally non-fimbriated margins, calyx with valvate aestivation and triangular to oval lobes, and concave petals with four appendages ( Plowman 1983, Loiola & Sales 2008). It is morphologically similar to E. citrifolium A. Saint-Hilaire (1829: 94) and E. daphnites Martius (1840: 363) by chartaceous or membranous, elliptic or oblong-elliptic leaf blades, stipules 3-setulose, glabrous and larger than the petioles, flowers with pedicels longer than 2.5 mm long, and styles of longistylous flowers free. However, it differs from E. citrifolium by the combination of triangular stipules 7–8.6 mm long with apex obtuse, margin irregularly denticulate, and 9 or 10 striated per side (vs. narrowly triangular 4–6(9) mm long, apex rounded, margin entire, 9–12 striated per side in E. citrifolium ), setae of stipules 1.7–2.6 mm long (vs. 0.5–1 mm long), spinules of the cataphylls brownish, 2–2.1 mm long (vs. darkish, 2–8 mm long), flower bud obovoid (vs. capitate or clavate), fascicles with 10–15 (vs. 1–9) flowers, two ovate bracteoles 0.6–0.9 mm long per flower (vs. two or three triangular bracteoles 2‒3 mm long), bracteoles margin erose (vs. entire), flowers 5–5.8 mm long (vs. 4.5–8 mm long), calyx 1.1–1.2 mm long (vs. 1.5–1.7 mm long), pedicels 2.9–3 mm long (vs. 2.8–5.5 mm long), petals 2.9–3 mm long, oblong-elliptic or elliptic (vs. 3–3.6 mm long, oblong-ovate), antepetalous and antesepalous stamens 2.4–2.5 mm and 1.9–2 mm long, respectively (vs. 1.2–1.8 mm long and 0.8–1.2 mm long). In addition to these characters, E. niquelandense are subshrubs or shrubs 0.75–1.8 m tall, with leaf blades 14–23.5 cm long, apex acuminate and 12–16 secondary veins per side, cataphylls measuring 7–7.3 mm long, different from the stipules in size, and fruits globose, ovoid or oblong, while E. citrifolium is commonly a tree 10(–15) m tall or sometimes a shrub 1–4 m tall, with leaf blades 7.1–15(20) cm long, apex acuminate and 11–14 secondary veins per side, cataphylls 4–6(9) mm long, similar to the stipules in size, and fruits always oblong. When compared to E. daphnites the characters listed in table 1 are useful to differentiate the two species.

Finally, according to the literature cited in the introduction to this article and supported by Loiola (2001), the shape and length of the stipules, petals, fruits, as well as the length of the stamens, setae of stipules and spinules of the cataphylls are informative for species discrimination in the genus.

Figures

FIGURE 1. Erythroxylum niquelandense M. J. Silva & Loiola. A. Fertile branch. B. Leaf. C. Detail of the midvein in the adaxial leaf surface. D. Petiole, adaxially canaliculate and transversely rugose. E. Stipule, dorsal view. F. Cataphyll, dorsal view. G. Fascicle with flower buds and open flowers. H. Flower bud. I. Bracteole, dorsal view, note erose margin. J. Brevistylous flower. K. Longistylous flower. L. Petal, ventral view. M. Ovary. N. Fruits. (From holotype, Illustrated by Cristiano Gualberto).

FIGURE 2. Erythroxylum niquelandense M. J. Silva & Loiola. A. Habitat and habit. B. Leaves and phylotaxy, note the conspicuous veins on the adaxial surface and slightly bullate leaf. C. Stipules. D. Stem and bark detail. E. Fascicle with flower bud, open flowers, and immature fruits. F. Immature fruits longitudinally striated, note the different shapes. G. Fruit in advanced stage of maturation with red apex. (Images taken by M. J. Silva)

FIGURE 3. Distribution map of Erythroxylum niquelandense M. J. Silva & Loiola in Goiás state, Central-West region, Brazil.