Paypayrola oppositifolia J.F.C Oliveira & L.P. Queiroz, 2024

Oliveira, José Florencio Cerqueira, Santos, Felipe Da Silva, Moreira, Ariane Dos Santos & Queiroz, Luciano Paganucci De, 2024, Two New Species Of Paypayrola (Violaceae) From The Campinaranas Of The Brazilian Amazon, Phytotaxa 665 (1), pp. 36-44 : 37-41

Paypayrola oppositifolia J.F.C Oliveira & L.P. Queiroz sp. nov. (Fig. 1,3)

Type: — BRAZIL. Amazonas: São Gabriel da Cachoeira, “São Felipe, margem direita do rio negro, terra firme, alta, mata alta”, 19 March 1952, R. L. Fróes 27944 (holotype IAN [74749]!).

Diagnosis:— Paypayrola oppositifolia is most similar to P. arenacea Aymard & G.A.Romero and P. pubiflora J.F.C Oliveira & L.P. Queiroz due to their occurrence in sandy soil regions and white corolla color, turning color when dry. However, P. oppositifolia can be distinguished from both species by having branches with thick, horizontally striated bark (vs. thin, smooth to vertically striated bark) and opposite leaves (vs. alternate to rarely subopposite). Additionally, P. oppositifolia can be distinguished from P. arenacea by having a tall stature, 3–8 m tall (vs. short stature, 1–2 m tall), petiole length of 5–15 mm (vs. 1–2 mm), and larger leaves (13) 15–25 (39) cm long (vs. 3–8 cm long). It also differs from P. pubiflora in having larger sepals (2–3.1 × 1.5–2 mm) and glabrous (vs. sepals 1.7–2 × 1.5–2 mm and pubescent), externally glabrous petals (vs. petals pubescent at the base or entirely pubescent on the outer part), and a glabrous ovary (vs. pubescent ovary).

Small tree to shrub, 3–7 m tall; branches glabrous, bark dark brown, thick, hard, brittle, horizontally striated, missing scale scars; apical buds, usually deciduous, scales 3–4 × 1–2 mm, glabrous, deltoid, rarely filiform, entire margins, glabrous, base truncate, acute apex; when present, lenticels elongated, depressed, brownish-gray. Stipules not observed, probably deciduous. Leaves opposite; petiole 5–15 × 2–5 mm, inflated at the base, rough to furrowed, blackened in young leaves, glabrous; blade (13) 15–25 (39) × 5–12 (15) cm, glabrous on both surfaces, oblanceolate to lanceolate, acuminate apex, entire margin, rarely repand to sinuate, attenuate to cuneate base, brochidodromous to camptodromous venation, 7–11 pairs of lateral veins, scalariform. Inflorescences pseudoracemes, terminal or ramiflorous, emerging below coeval leaves, rachis 3–7 (10) cm long, glabrous, peduncle 5–10 mm, glabrous, brachyblasts usually 3-flowered, central flower older than the two lateral ones, flowers congested on the rachis; bract (at the base of the peduncle) 3–4 mm long, deltoid, glabrous; bracteole (at the base of the pedicel) ca. 1 mm long, deltoid, glabrous, rarely ciliate on the margin; pedicel ca. 1 mm long, glabrous. Flowers 6–20 mm long; sepals 2–3.1 × 1.5–2 mm, subequal, imbricate, oval, glabrous, base truncate to rounded, margin entire, glabrous to ciliate, rounded to obtuse apex, 1–3 visible veins when rehydrated, usually with an appendix over the midvein, globose to fusiform; petals 10–15 × 1.6–2 mm, white, changing color when dry, lanceolate to linear, glabrous, truncate base, glabrous or ciliate margins at the base, obtuse to rounded apex; stamens 1.5–2.3 mm long, filaments fused into a tube ca. 1 mm long, glabrous, anthers glabrous, connective appendix barely visible <0.2 mm long, brownish-orange, glabrous; ovary 1.8–2 × 0.7– 0.14 mm, ovoid to pyriform, glabrous, style 1.5–2 mm long, straight, glabrous, stigma truncated. Fruits capsules, each valve 20–25 × 5–7 mm, completely glabrous. Seeds 2–3 per valve, 8–9 × 5–6 mm, oblong to ellipsoid, glabrous, caruncle globose, ca. 2 mm long.

Distribution, habitat, and phenology: Paypayrola oppositifolia is known only from the Brazilian state of Amazonas, in the regions of the Negro River basin (Uaupé and Içana rivers) and the Solimões River basin (Coari and Tefé). It occurs in Campinarana, a type of Amazonian vegetation characterized by low forest over dystrophic white sand soil ( IBGE 2012), with a distinct flora rich in endemism ( Fernandes 2006). It was collected with flowers in July and from October to November, and with fruits in November ( Fig 3 ).

Conservation status: We assessed the conservation status of Paypayrola oppositifolia as Endangered (EN) according to IUCN (2022) criteria B1ab(iii) + B2ab(iii), as it presents an EOO 84.2 km ² and an AOO 20 km ². The new species has a restricted occurrence to campinaranas regions on sandy soil, with records only for the municipalities of Coari, São Gabriel da Cachoeira, and Tefé in the state of Amazonas.

Etimologia: The specific epithet ‘oppositifolia’ refers to the exclusively opposite phyllotaxy, a unique characteristic within the genus, which typically has species with alternate or rarely subopposite leaves.

Additional specimens examined (paratypes): Brazil: Amazonas : Coari , Base de operações Geólogo Pedro de Moura , rio Urucu. Projeto CTPetro— Dinâmica de clareiras ( DICLA) Mata de terra firme CI-P3-46. 04°53’02,6”S, 65°13’50,6”W, 27 October 2004 [fl.], M. N. C Bastos & L. C. B. Lobato 2481 ( MG [180805]!). São Gabriel da Cachoeira, Rio Uaupés, Ipanuré, estrada para Urubuquara. Caatinga alta sobre solo arenoso, 17 November 1987 [fl.], H. C. Lima 3207 ( HUEFS [263611]!, INPA [181580]!, RB [427148]!) ; Rio Uaupés , Taraquá, 08 November 1947 [fl.], J. Murça-Pires 917 ( IAN [30365]!) ; Rio Uaupés , Taraquá, 08 November 1947 [fl.], J. Murça-Pires 1914 ( IAN [50089]!) ; Rio Uaupés , Taraquá, 10 November 1947 [fl.], J. Murça-Pires 986 ( IAN [30420]!) ; Rio Uaupés , Taraquá, caatinga próxima à serra, 10 November 1947 [fl.,fr.], J. Murça-Pires 1005 ( IAN [30437]!) ; São Felipe , Rio Içana , mata de caatinga 21 September 1952 [fl.], R. L. Fróes & G. Addison 28654 ( IAN [78243]!). Tefé , Estrada do Luc 3— Porto Urucú, 16 July 1991 [fl.], A. S. Tavares et al. 422 ( INPA [198718]!) .

Notes: Paypayrola oppositifolia is unique within the genus for having opposite leaves ( Table 1) (vs. alternate or less frequently subopposite leaves in other species of the genus) and branches with thick, horizontally striated bark (vs. smooth to vertically striated bark in other species of the genus). Along with P. arenacea and P. pubiflora , P. oppositifolia shares the occurrence in sandy soil regions and the white corolla color, turning color when dry. However, P. oppositifolia can be additionally distinguished from P. arenacea by having large leaves (13) 15–25 (39) cm long (vs. leaves 3–8 cm long) and petals with entirely glabrous margins or ciliate only at the base (vs. petals with ciliate apex), and from P. pubiflora in externally glabrous petals (vs. petals pubescent at the base or entirely pubescent on the outer part) and a glabrous ovary (vs. pubescent ovary).

Among the species occurring in the Brazilian Amazon, Paypayrola oppositifolia shares with P. guianensis and P. grandiflora a similar leaf blade shape and size. However, it differs from both species by predominantly occurring in sandy soil (vs. predominance in clayey soil in P. guianensis and P. grandiflora ), having opposite leaves (vs. alternate leaves rarely subopposite in both species), a pseudoraceme with densely congested flowers on the rachis (vs. pseudoraceme with lax flowers on the rachis in both species), and white petals (vs. yellow petals in both species).

Figures

FIGURE 3. Geographic distribution of Paypayrola oppositifolia and Paypayrola pubiflora.