Lycianthes amazonica Costa-Silva & Agra, 2021

Costa-Silva, Rafael, Giacomin, Leandro Lacerda & Agra, Maria De Fátima, 2021, A new species and taxonomic notes on Lycianthes series Glanduliferae (Solanaceae) from the Brazilian Amazon, Phytotaxa 527 (1), pp. 51-59 : 53-57

Lycianthes amazonica Costa-Silva & Agra , sp. nov. ( Figs. 1 , 2 , 3 ).

Species endemic to Brazil. Similar to L. sprucei , from which it differs by its sessile inflorescences with 1–2-flowers, calyx with 10-appendages, all equal, linear (vs. inflorescence 2–4-flowers, calyx with 10–appendages, unequal, linearlanceolate in L. sprucei ); the leaves ovate to orbicular, the larger ones with 8–10 primary veins, blades 7.0–15 × 4.0– 8.5 cm (vs. leaves obliquely lanceolate to elliptic, the larger ones with 5–6 primary veins, laminas 8.0–11 × 3–4.5 cm in L. sprucei ); indument golden to yellowish of predominantly 1–furcate, glandular trichomes (vs. indument ferruginous of stipitate, 2–furcate, eglandular or glandular trichomes).

Type: — BRAZIL. State of Pará: Municipality of Itaituba , Estrada Santarém-Cuiabá, BR 163 , km 1007 a 1012, 15 May 1983 (fl, fr), M. N . Silva et al. 348 (holotype: RB 851548!; isotypes: INPA 113470 !; K 1071890 !; MG 11859 !; NY 1291273 !; US 01936228!).

Scandent shrubs, l.0–3.0 m tall, branched, perennial; branches and stems terete, ferruginous to brown, striate to rugose, indument dense strigose, golden, yellowish to ferruginous, trichomes simple, multicellular, uniseriate, and bifurcate with glands on the tips. Sympodial units difoliate, geminate; leaves simple; petiole 5.0 – 8.8 mm long, grooved, tomentose, ferruginous, trichomes similar to those of branches; lamina chartaceous, 7.0–14.5 × 4.0– 8.5 cm, weakly discolored, ovate to large elliptic, 8–10 primary veins, impressed on the adaxial surface, prominent on the abaxial surface, strigose on both surfaces, densely strigose on the midrib, golden to yellowish, trichomes simple, 1–celled, multicellular uniseriate, glandular-stalked, simple or bifurcate, glandular at the apex; apex acuminate, margin entire to slightly sinuate, ciliate, base cuneate and somewhat oblique. Inflorescence with 1–2 flowers, axillary, sessile; pedicel 1.5–2.5 cm long, enlarged in fruit, pendulous, erect at maturity, terete, dense strigose, yellowish to ferruginous, trichomes similar to those of the stem. Flowers all perfect, 5-merous, monoclinous; calyx cupuliform, densely strigose, truncate at the apex, 6.0–7.0 x 8.0–9.0 mm; with 10–appendages, all equal, linear, emerging from 1.3–1.5 mm below the calyx rim, 0.5–1.5 cm long, pubescent, golden to yellowish, trichomes similar to those of the pedicels; corolla campanulate, plicate, white, 1.8–2.0 cm diam., lobes lanceolate, 0.8–1.2 x 0.3–0.4 cm, pilose at the upper half of the outer surface, trichomes simples, interpetalar tissue glabrous, well-developed, 0.3–0.4 cm wide; stamens 5, unequal (1 + 4), the largest, 4.5–5.0 mm long, the 4 smaller ones with shorter filaments, 1.9–2.2 cm long, anthers yellow, attenuate from the base to the apex, the larger 6.0– 6.2 mm long, the smaller ones 5.8–6.0 mm long, all sub-sagittate to slightly asymmetric at the base, 1.5– 2.0 mm wide, with extrorse pores; ovary conical, glabrous; style glabrous 1.0– 1.1 cm length, straight, slightly curved to the apex, stigma oblong-clavate, 1.0– 1.5 mm long, minutely papillose, bright green. Fruit a globose berry, 2.0–3.0 cm in diameter, glabrous, green to yellow-green when immature, red when ripe, drying brownish or black, the epicarp leathery; fruiting calyx enlarged, persistent, the calyx appendages equal, linear-subulate, radiate, recurved, 0.8–3.0 cm long, strigose, golden to yellowish; pedicel upright, enlarged, 1.5–4.0 cm long, trichomes glandular and furcate, like those of the stem. Seeds up to 20 per fruit, ovoid to sub-reniform, compressed, 2.7–3.4 × 2.9–3.5 mm, seed coat slightly waved, reticulated, beige to light brown.

Distribution, habitat and phenology: –Endemic to Brazil and so far only known from the North region, in Pará state, in two localities, both supposedly at Itaituba municipality ( Fig. 3 ). The habitat of L. amazonica can be described as secondary formations (capoeira) of terra-firme forests along the BR-163. Although the records precisely cite kilometers 1000 and 1012 and at 1203 of BR-163, these site marks are no longer the same, and it is hard to predict with precision where collections were gathered. The known collections are all supposedly from roadsides, expectedly on clay or rocky soil. Flowering and fruiting samples were collected in May and November, associated with the peak of the rainy season and the dry season in the region.

Conservation status:— ”Data deficient” (DD; IUCN 2019). The coordinates attributed to the collections does not allow an EOO estimation and an AOO of 8 km 2 (CR) is drawn, considering the two localities. Nevertheless, considering how imprecise are the localities in the known collections and that data on population size and species abundance is insufficient, Lycianthes amazonica should be classified as “Data deficient” (DD), according to the IUCN criteria. We strongly recommend that efforts should be taken to gather more information on the species distribution, as current data suggest it might be threatened of extinction and the region to where it is found in place to the highest deforestation rates in the Brazilian Amazon, as part of what is called the “deforestation arc” ( Carrero et al. 2020, INPE 2020).

Etymology:— The specific epithet of L. amazonica refers to the area of its distribution, as it was only found in the Amazon, a biome that, in Brazil, occupies almost half (49.2%) of its territory and covers three of the five regional divisions of the country (North, Northeast and Midwest), being the largest terrestrial biome in the country.

Additional specimens examined (Paratypes):— BRAZIL. Pará: Municipality of Itaituba , BR 163 , km 1203, Cuiabá-Santarém highway, km 1203, 17 Nov 1977 (fl), A. S . Silva et al. 253 (INPA, NY).

Discussion:— The morphological characters of Lycianthes amazonica , such as its scandent habit, ferruginous indument with bifurcate glandular trichomes, calyx appendages equal and linear, inflorescences with 1–3 flowers, and stamens with unequal filaments allow us to place this species in Lycianthes subg. Polymeris sect. Eupolymeris ser. Glanduliferae Bitter (1919:380) . The series Glanduliferae was proposed by Bitter (1919) based on the remarkable similarity of the types of the glandular trichomes observed on leaves of L. magadalenae ( Dunal 1852:173) Bitter (1919:381), L. purpusii ( Brandegee 1914:62) Bitter (1919:382), and L. sprucei (Van Heurck & Müll. Arg. 1870:67) Bitter (1919:380) , which highlighted the need to place them in a separate group. These types of trichomes were also present in L. amazonica , and for this reason we placed this new species in the series Glanduliferae , while no broad sampling phylogenetic study is available to the group to test the monophyly of Bitter´s proposed groupings. A set of characters, however, can differentiate them from each other, such as leaf shape, indument, inflorescence, pedicel, calyx appendages, and corolla color (see Table 1 ).

Lycianthes amazonica is closely related to L. sprucei , a species from Peru: both species have scandent or vine habit, flexuous branches, indument ferruginous with glandular trichomes. Lycianthes amazonica differs from L. sprucei in having only bifurcate glandular trichomes, leaves ovate or oval-elliptic, indument strigose, and a remarkably different geographic distribution, endemic to Brazil (vs. leaves obliquely lanceolate to elliptic, indument ferruginous of stipitate, 2-furcate, eglandular or rare glandular trichomes in L. sprucei ).

Lycianthes amazonica was previously identified as L. pauciflora (Vahl) Bitter (1919: 341), probably due to both have scandent shrubby habit, white corollas, and their occurrence in the Brazilian Amazon. Although the flora of the upper Tapajós River basin is still poorly known, L. amazonica and L. pauciflora are expected to occur in sympatry. Lycianthes amazonica differs from L. pauciflora in having sympodial units difoliate (vs. unifoliate in L. pauciflora), simple uniseriate, multicellular, and bifurcate glandular trichomes (vs. stellate and simples non glandular trichomes), strigose indument (vs. tomentose), and calyx appendages equal, glandular pubescent (vs. calyx appendages unequal, stellate-pubescent).

Figures

FIGURE 1. Holotype of L. amazonica Costa-Silva &Agra held at RB herbarium (Silva 348). The image is a courtesy of the RB Herbarium, Jardim Botânico do Rio de Janeiro.

FIGURE 2. Lycianthes amazonica Costa-Silva &Agra:indument and trichomes.A. Detail of adaxial leaf surface, and yellowish indument of young fruit (bar = 2 cm). B. Detail of abaxial leaf surface, and flower calyx with yellowish indument (bar = 1 cm). C. Capitate glandular and bifurcate trichomes (SEM, bar = 10 µm). D. Detail of the glandular portions of trichomes (SEM, bar = 10 µm). E. Simple and furcate glandular trichomes (SEM, bar= 20µm). F. Detail of the glandular portion of the glandular trichome from leaf (SEM, bar = 2µm). From M. N. Silva et al. 348 (RB).

FIGURE 3. Known distribution of Lycianthes amazonica Costa-Silva & Agra (black dots) in southern Pará State, Brazilian Amazon.