Paepalanthus farinaceus F.N. Costa, Andrino & Trovó, 2016

Costa, Fabiane Nepomuceno, Andrino, Caroline Oliveira, Trovó, Marcelo, Echternacht, Livia & Sano, Paulo Takeo, 2016, Three new micro-endemic species of Paepalanthus (Paepalanthoideae, Eriocaulaceae) from Serra do Ambrósio, Minas Gerais, Brazil, Phytotaxa 247 (2), pp. 118-126 : 122-123

Paepalanthus farinaceus F.N. Costa, Andrino & Trovó , sp. nov. ( Figs. 1F–H , 2C , 4 )

Type:— BRAZIL. Minas Gerais: Rio Vermelho, Serra do Ambrósio, Vargem do Anjo, próximo à Comunidade de Pedra Menina, 1248 m elev., 18°08’19.1”S, 43°01’06.8”W, 26 June 2012, F. N. Costa, A. B. Sampaio, R. Ramos & S. N. Fonseca 1538 (holotype DIAM!, isotypes B!, NY!, SPF!)

Paepalanthus farinaceus is characterized by its leaves, spathes, scapes, and involucral bracts, which are whitish and densely sericeous.

Perennial herbs. Rhizome not thickened, 1–2 cm long. Leaves rosulate, flat to reflexed, whitish, chartaceous, lanceolate, 4.0–11.0 × 0.3–0.7 cm, densely sericeous on both surfaces, margin pilose, apex acute. Spathes appressed to the scapes, chartaceous, 3.5–7.0 cm long, densely sericeous, margin ciliate, apex acute. Scapes ca. 2–24 per rosette, whitish, 11–24 cm long, multicostate, sericeous to glabrescent. Capitula spherical, 0.8–1.5 cm diam. Involucral bracts in 2–4 series, cream, lanceolate, ca. 4–7 × 2–3 mm, glabrous on adaxial surface, sericeous abaxially, margin ciliate, apex acute. Flowers 3-merous, ca. 190 per capitula: 5× more staminate than pistillate. Floral bracts light brown to blackish, linear to lanceolate, ca. 4–5 mm long, glabrous on adaxial surface, pilose toward the acute apex. Staminate flowers ca. 4–5 mm long, excluding the pedicel; pedicel ca. 0.3 mm long, with long and numerous trichomes; sepals free, membranaceous, obovate, ca. 3 mm long, glabrous on both surfaces, margin ciliate; corolla tubular, membranaceous, castaneous to cream, hyaline, glabrous; stamens ca. 4 mm long, anthers cream; pistillodes 3, papillose. Pistillate flowers ca. 4–5 mm long, excluding the pedicel; pedicel ca. 0.2 mm long, with long and numerous trichomes; sepals fused at the base, membranaceous, cream to blackish, lanceolate, ca. 4 mm long, glabrous on both surfaces, margin ciliate towards the obtuse apex; petals membranaceous, hyaline, lanceolate, ca. 3 mm long, glabrous on both surfaces, margin ciliate; gynoecium ca. 3 mm long, stigmatic branches bifid at the apex, 1× longer than the nectariferous branches; staminodes 3, scale-like. Seeds reddish to brown, ellipsoid, striate.

Etymology: —The epithet “ farinaceus ” refers to the highly dense indumentum of the leaves, spathes, scapes, and involucral bracts, which give a whitish appearance to the plant.

Distribution and habitat: —The species is known from a single locality, probably consisting of two subpopulations on the mountain known locally as Espigão do Meio, in Serra do Ambrósio. Paepalanthus farinaceus is terrestrial and occurs in a transition zone between Cerrado sensu stricto and Campos Rupestres, amongst a strongly branched shrubby vegetation locally called Carrasco, above 1240 meters of elevation. The soil is quartzitic, white and with a coarse, sandy to gravelly texture ( Figs. 2A , 4 ).

Conservation: —The species is confined to occupy an area of eight km 2 and the subpopulations are not included in any protected area. Due to its very narrow distribution and proximity to mining sites of sand extraction, it is considered critically endangered (CR) according to criteria B2ab (i, ii, iii,iv, v) and C2a (i) ( IUCN 2011).

Discussion: — Paepalanthus farinaceus is easily recognized by its whitish green leaves, spathes and scapes (see Fig. 2C ), due to a dense sericeous vestiture of white trichomes, together with stramineous to cream-colored involucral bracts covered by the same kind of white trichomes. Paepalanthus farinaceus is morphologically similar to P. argyrotrychus , also described here, both with approximately the same general habit, given by the leaves (rosulate, flat to reflexed, lanceolate, chartaceous and sericeous) and spathes (densely sericeous). However, P. farinaceus has whitish and sericeous to glabrescent scapes (vs. golden and glabrous), and cream and abaxially sericeous involucral bracts (vs. brown and glabrous abaxially). Individuals with flowers and fruits were collected between June and July. The sepals are fused at the base and possibly even play a role in ejecting the fruit from the inflorescence in wind dispersal, as described by Hensold (1988), Trovó & Stützel (2011) and here for Paepalanthus argyrotrychus .

Additional specimens examined (paratypes):— BRAZIL. Minas Gerais: Rio Vermelho, Pedra Menina, Morro do Ambrósio , 15 July 1984, A. M. Giulietti CFCR 4516 , M. G. Wanderley, E. Varanda, A. Furlan & R. M. Harley ( SPF) ; Serra do Ambrósio , 1509 m elev., 18°06’24.1”S, 43°02’15.4”W, 23 October 2013, R. R. Silva & S. N. Fonseca 109 ( DIAM) .

Figures

FIGURE 1. Paepalanthus argyrotrychus F.N. Costa, Andrino & Echtern. A. Habit. B. Capitulum with flowers at anthesis. C. Involucral bract, abaxial surface. D. Pistillate flower. E. Staminate flower. Paepalanthus farinaceus F.N. Costa, Andrino & Trovó. F. Habit. G. Capitulum with flowers at anthesis. H. Involucral bract, abaxial surface. Paepalanthus velutiphyllus F.N. Costa, Andrino & Sano. I. Habit. J. Leaf, adaxial surface. (Drawn from the holotypes).

FIGURE 2. A. Top of the mountain Espigão do Meio, in Serra do Ambrósio. B. Habit of Paepalanthus argyrotrychus F.N. Costa,Andrino & Echtern. C. Habit of Paepalanthus farinaceus F.N. Costa, Andrino & Trovó. (Photos by F.N. Costa).

FIGURE 4. Map showing the distributions of three new species.