Vochysia microphylla G. Shimizu & K. Yamamoto, 2012

Shimizu, Gustavo Hiroaki, Rodrigues, Licléia Da Cruz & Yamamoto, Kikyo, 2012, Vochysia microphylla (Vochysiaceae), a new species from Serra do Cipó, Minas Gerais, Brazil, Phytotaxa 56 (1), pp. 10-14 : 10-13

Vochysia microphylla G. Shimizu & K. Yamamoto , sp. nov. ( Figs. 1 and 2 )

Vochysia microphylla is characterized by the cespitose growth habit, very small leaves (up to 2 cm) and inflorescences (3–3.5 cm). Also this is the only species of Vochysia sect. Ciliantha subsect. Lutescentes with both petals and stamen glabrous.

Type:— BRAZIL. Minas Gerais: Morro do Pilar, Parque Nacional da Serra do Cipó , trilha para as velózias gigantes, 19º14’48’’S, 43º30’42’’W, 1256 m, 14 May 2010, fl. and fr., Shimizu 231 ( UEC!) .

Cespitose shrub with many clustered stems, ca. 1.5 m tall, well-branched. Branchlets cylindrical, slender, internodes longitudinally striate, glabrous, cortex not exfoliating. Leaves in 4(–6)-merous whorls; stipules 1 mm long, persistent; petiole 1 mm long, glabrous; leaf blade 0.8–2 × 0.4–1.2 cm, oblong to obovate, chartaceous; adaxial surface glabrous, midrib flat and secondary veins prominulous; abaxial surface glabrous, excepting some trichomes at apex, midrib prominent and secondary veins prominulous; apex retuse, base rounded to cuneate, margin flat. Inflorescence a thyrse of cincinni, terminal, 3–3.5 cm long, pubescent; cincinni 2–3-florous, peduncle ca. 0.5 cm long and pedicel 0.3–0.7 cm long; bracts caducous. Flower bud 10– 12 × 1.5–2 mm, straight to sub-incurved, cylindrical, apex acute or acuminate; spur 3–5 × 1 mm, straight or incurved, cylindrical, apex globose; spurred sepal 10–11 mm long; remaining 4 smaller calyx lobes 2 mm long, ovate, apex obtuse. Petals 3, both surfaces glabrous, central one 5–8 × 1–2 mm, lateral ones 4–6 × 1–2 mm. Stamen 1, filament 2–3 mm long, anther 8–11 mm long, glabrous; staminodes 2, 0.5–0.6 mm long, glabrous. Ovary 2 × 1.5 mm, deltoid, glabrous; style 8.5–15 mm long, cylindrical but with the upper half slightly clavate, straight to incurved, glabrous; stigma subtriangular, subterminal. Capsule 2–2.3 × 1.1–1.3 cm, ovoid to oblong-ovoid, apex subtruncate to rounded, the surface verruculose and glabrous. Seed elliptic, laterally flattened, winged, 2.2 × 0.7 cm.

Distribution and habitat: — Vochysia microphylla is only known from “campo rupestre” vegetation in Morro do Pilar and Itambé do Mato Dentro, within the Serra do Cipó area. Few individuals have been found, one at the trail that leads to the populations of Vellozia gigantea N.L. Menezes & Mello-Silva (1999: 537) , from which the holotype and all the paratypes, except Borges & Santos 279 and Rodrigues 81, were collected, about five individuals near the ICMBio lodging at Alto do Palácio, from one of which Rodrigues 81 was collected, and one in Cabeça de Boi area, ca. 20 km far from the other collection places.

Phenology: —One individual was collected with flowers in May and October, and with fruits in May, July, and October; another one with flowers in November and the last one with flowers in December.

Conservation status: —According to the IUCN Red List ( IUCN 2011), the species can be assigned as critically endangered (CR, criterion D2–very small or restricted population) due to the few individuals known from few places.

Etymology: — The specific epithet refers to the very small leaves, so far the smallest ones ever found in the genus.

Additional specimens examined (paratypes): — BRAZIL. Minas Gerais: Itambé do Mato Dentro, Santana do Rio Preto, Cabeça de Boi , 17 December 2007, fl., Borges & Santos 279 ( SPF!) ; Morro do Pilar, Parque Nacional da Serra do Cipó, Alto do Palácio , 19º15’S, 43º31’W, 1400 m, 16 November 2007, fl., Rodrigues 81 ( BHCB!, UEC!) ; trilha para as velózias gigantes, 19º14’48’’S, 43º30’42’’W, 1256 m, 23 July 2008, fr., Shimizu et al. 62 ( BHCB!, SPF!, UEC!) ; 2 October 2008, fl. and fr., Shimizu et al. 137 ( UEC!) ; 28 October 2008, fl., Shimizu et al. 201 ( BHCB!, SPF!, UEC!) .

Discussion: — Vochysia microphylla belongs to section Ciliantha Stafleu (1948: 445) subsection Lutescentes ( Warming 1875: 60) Stafleu (1948: 457) due to the glabrous ovary, the mostly glabrous adult branchlets and leaves, and the cortex which is never exfoliating. In this subsection, V. microphylla is the only species that has both stamen and petals glabrous. Those organs are ciliate in all other species of this subsection, or only one of them is glabrous. Although looking like a miniature V. thyrsoidea Pohl (1831: 24) , a tree species with leaves in 4(–6)-merous whorls, and sharing the same leaf, flower bud, spur apex and fruit shape, the new species has a very different habit. The globose spur apex, shared with V. thyrsoidea , is very distinctive among the species of subsection Lutescentes from the savanna formations of the Brazilian inland.

It could also be confused with V. pygmaea Bongard (1839: 7) and V. rotundifolia Martius (1826: 140) , two other shrubby species that occur in Serra do Cipó ( Shimizu 2009). They can be distinguished mainly by the number of leaves per whorl, leaf and inflorescence length, spur apex shape, and indument in petals and stamen ( Table 1). Vochysia martiana Stafleu (1948: 478) and V. cipoana Stafleu (1954: 409) will be synonymized under V. pygmaea and V. rotundifolia , respectively, in an upcoming paper.

Figures

FIGURE 1. Vochysia microphylla. A. Flowering branch. B. Lateral petals. C. Central petal. D. Calyx, with spurred sepal apart. E. Anther. F. Gynoecium. G. Fruit. H. Seed. A–D after Shimizu 231; E, F after Rodrigues 81; G, H after Shimizu et al. 137; drawn by W. Forster.

FIGURE 2. Vochysia microphylla. A. Population showing the cespitose growth habit. B. Well-branched individual from Vellozia gigantea trail. C. Flowering branch with flower buds. D. Flowering branch with open flowers. A. Photo L.C. Rodrigues. B–D. Photos G.H.Shimizu.