Phyllanthus pedrosae J.C.R.Mendes, J.M.A.Braga & Fraga, 2024

Mendes, Jone Clebson Ribeiro, Braga, João Marcelo Alvarenga, Fraga, Claudio Nicoletti de & Athiê-Souza, Sarah Maria, 2024, Phyllanthus novofriburgensis and P. pedrosae, two new species of Phyllanthus subsect. Clausseniani (Phyllanthaceae) from Southeastern Brazil, European Journal of Taxonomy 935, pp. 293-306 : 298-299

Phyllanthus pedrosae J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov.

urn:lsid:ipni.org:names:77342726-1 Figs 1G‒M , 3–4 ; Table 2

Diagnosis

Diagnostic characteristics in relation to other species in the subsection: subshrubby habit, 1.5‒2 m tall, stems and branches angular, smooth. Leaf blade membranaceous, ovate to elliptical, apex mucronate. Cymules axillary, unisexual; staminate flowers 1 or 2 close to the branch axil and solitary pistillate flowers distally positioned. Staminate pedicel 12‒13 mm long and pistillate pedicel 8.5‒10 mm long. Fruit pedicel 10‒12 mm long, capsules 3‒5 mm in diam., oblate.

Etymology

The specific epithet is a tribute to Luciano Pedrosa, an independent botanist and great connoisseur of the flora of Minas Gerais, responsible for numerous collections that have contributed to the knowledge of the flora in this region.

Type material

Type BRAZIL – Minas Gerais • Ouro Preto, Parque Estadual do Itacolomi , campo ferrugíneo ; 20°25′08″ S, 43°30′24″ W; 1470 m a.s.l.; 3 May 2021; fl., fr.; J.C.R. Mendes 222; holotype: PEUFR [PEUFR55853!] ; isotypes: OUPR, RB .

Paratypes BRAZIL – Minas Gerais • Ouro Preto ; 27 May 1995; fl.; M.C.T.B. Messias s.n.; OUPR [1701], PEUFR • same data as for preceding; 1 Nov. 1996; fl., fr.; M.C.T.B. Messias s.n; OUPR [6395], PEUFR • same data as for preceding; 16 May 2000; fl.; M.C.T.B. Messias 350; OUPR, PEUFR • same data as for preceding; 20 Jun. 2023; fl.; J.C.R. Mendes et al. 390; OUPR, PEUFR.

Description

Subshrub 1.5‒2 m tall, prostrate, monoecious. Stem angular, smooth, glabrous. Cataphylls present. Branching non-phyllanthoid. Branches erect, angular, smooth, glabrous, pinnatiform; stipules up to 1 mm long, slightly triangular, glabrous. Petiole 1.5‒2 mm long, cylindrical, glabrous. Leaf blade 11‒16 × 9‒11 mm, membranaceous, ovate to elliptical; base cuneate; apex mucronate; adaxial and abaxial sides glabrous, adaxial side dark green and abaxial side light green; margin revolute; venation brochidodromous, 8‒9 pairs of secondary veins. Inflorescence a simple cyme, axillary, unisexual; cymules with 1 or 2 staminate flowers close to the branch axil and solitary pistillate flowers distally positioned; bracts up to 1 mm long, triangular. Staminate flowers with pedicel 12‒13 mm long; sepals 5, 1.8‒2 × ca 2 mm, biseriate, orbicular, apex rounded, glabrous on both sides, pink, midrib evident; glandular disc 5-segmented, alternisepalous, cuneiform, surface glandular; stamens 3, filaments completely free, 0.8‒1 mm long; anthers deeply emarginate, with vertical dehiscence; pollen grains 4-colporate. Pistillate flowers with a 8.5‒10 mm long pedicel; sepals 5, 1‒1.5 × ca 2 mm, biseriate, broadly obovate, apex rounded to slightly obtuse, glabrous on both sides, pinkish to pinkish-green, midrib evident; glandular disc entire, patelliform, smooth; ovary up to 1.8 mm in diam., 3-locular, oval; styles 3, united at base, up to 1 mm long; stigma 2-parted, parallel, subcapitate. Capsules 3‒5 mm in diam., oblate, 6-mericarp, dark green, glabrous, calyx and stigma persistent; fruit pedicel 10‒12 mm long. Seeds 1.8‒2 mm long, trigonous; hilum terminal, ovate; verrucous ornamentation with regularly arranged stellate ribs; dark brown.

Distribution, habitat and phenology

Phyllanthus pedrosae sp. nov. is found in the phytogeographic domain of Cerrado in the city of Ouro Preto, state of Minas Gerais, Brazil, growing on slopes of rocky outcrops, close to watercourses in the Parque Estadual do Itacolomi, in altitudinal ranges between 1470 and 1600 m ( Fig. 3 ). It was collected with flowers and fruits in May and November; and with flowers in May and June.

Preliminary conservation assessment

Phyllanthus pedrosae sp. nov. is categorized as Critically Endangered (CR), sub-criterion B2ab(ii,iv) due to its AOO of 4000 km 2. Although this species has abundant populations and is inserted in the context of a protected area, we believe that the species faces many threats due to the uncontrolled deforestation process in the surroundings of the Parque Estadual do Itacolomi and because the region is heavily visited by tourists.

Figures

Fig. 1. A‒F. Phyllanthus novofriburgensis J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. A. Branches. B. Leaf blade. C. Cymule. D. Staminate flower. E. Pistillate flower. F. Capsule. G‒M. Phyllanthus pedrosae J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. G. Branches. H. Branch detail [angular]. I. Leaf blade [in detail the mucronate apex]. J. Staminate flower. K. Pistillate flower. L. Capsule. M. Seed. Illustration designs based on type specimens by Regina Carvalho.

Fig. 3. Distribution map of Phyllanthus novofriburgensis J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. (white square) and P. pedrosae J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. (white circle). State abbreviations: ES = Espírito Santo; MG = Minas Gerais; RJ = Rio de Janeiro; SP = São Paulo.

Fig. 4. Phyllanthus pedrosae J.C.R.Mendes, J.M.A.Braga & Fraga sp. nov. A‒B. Habitat. C. Branches (in detail the shape of the branches, as well as the apex of the leaf blade).D. Floral branches. E. Branches with a staminate flower in detail. F‒G. Capsule. Photos by J.C.R. Mendes (A–B), L. Pedrosa (C–E) and F–G by M.C.T.B. Messias (OUPR [6395]).