Peltaea rupestris, Fernandes-Júnior, Aluisio J. & Esteves, Gerleni L., 2016

Fernandes-Júnior, Aluisio J. & Esteves, Gerleni L., 2016, Three new species of Peltaea (Malvaceae, Malvoideae) from the cerrado of Brazil, Phytotaxa 255 (1), pp. 75-82 : 78-80

Peltaea rupestris A.J.Fernandes-Jr. & G.L.Esteves sp. nov. Type:— BRAZIL. Minas Gerais: Augusto de Lima, 32,5 Km da ponte do Rio da Onça , na estrada para Francisco Dumont , 17°45’S, 44°12’W, 25 March 2000 (fl, fr), L.R. Lima et al. 119 (holotype SPF!) . Figures 1I–Q , 3B–D .

Similar to Peltaea riedelii , but differing in having branches with a longitudinal line of both stellate and simple trichomes (vs. only stellate trichomes), leaf blades coriaceous (vs. chartaceous), 5–7-palmativeined (vs. 3-palmativeined), bracteoles of epicalyx spathulate (vs. peltate) with stellate and glandular trichomes on adaxial surface (vs. stellate trichomes), calyx 15-veined (vs. 25-veined), petals obdeltoid (vs. obovate), mericarps with simple and glandular trichomes (vs. only simple trichomes) and column conic (vs. cylindrical, slightly enlarged at base).

Shrubs 0.5–1.5 m tall, with xylopodium; branches grooved and flattened at the apical portion, with stellate adpressed trichomes associated with a longitudinal line of stellate and simple trichomes. Stipules 4–5 mm long, subulate; petioles 1–4 mm long; leaf blades 3.9–8.8 × 1–3.3 cm, elliptic to ovate, coriaceous, palmate with 5–7 basal veins, apex acute, base rounded or subcordate, margin irregularly serrate, both surfaces with stellate adpressed trichomes. Flowers chasmogamous, solitary and/or in terminal reduced racemes (capituliform), always subtended by foliaceous bracts; pedicels 0.5–5 mm long; bracts 2.1–4.2 × 1.2–1.9 cm, elliptic-ovate to ovate, both surfaces with stellate adpressed trichomes, adaxial surface with a reddish spot at the base, often ciliate at the basal portion; bracteoles of epicalyx 8–9, spathulate, both surfaces with stellate trichomes, pedicels 4–7 mm long, blade 2–4 × 0.7–1 mm, narrowly elliptic, adaxial surface with glandular trichomes, margin ciliate; calyx 7–10 mm long, 15-nervate, internally with simple and glandular trichomes, externally with stellate and simple trichomes; petals 2.1–2.6 × 1.5–2.8 cm, pink with a red basal spot, obdeltoid; staminal tube 1.1–1.7 cm long, with glandular trichomes, free parts of the stamens distributed in 2 groups along the tube; styles erect, with glandular trichomes. Mericarps 4.5–5 mm long, muticous, dehiscent, dorsal side smooth, with simple and glandular trichomes; column 0.7–1 mm long, conic; seeds 2.6–3 mm long, trigonous, glabrous.

Distribution and habitat: —Endemic to the state of Minas Gerais, Brazil, in the Espinhaço Mountain Range, growing on rocky outcrops at elevations between 950 and 1210 m ( Figure 4 .)

Phenology: —The new species was collected in flower in March, April, June, August, September and November, and in fruit in March and April.

Etymology: —The epithet refers to rocky mountain environment of the type locality.

Conservation status: — Peltaea rupestris is known from only five localities, two of them in protected areas and in a highly deforested area. Besides that, the species has considerably small EOO (279,890 km 2) and AOO (16 km 2) ( Bachman et al. 2011), severely fragmented population, and is directly threatened by deforestation. Thus, following the IUCN recommendations ( IUCN 2014), P. rupestris should be considered Endangered [EN, B2ab (iii, iv)] in its overall distribution.

Notes and taxonomic affinities: —The main characters that distinguish P. rupestris are related to the leaf blades, mainly the rough surface, coriaceous consistency, and the presence of stellate adpressed trichomes on both surfaces, the bracteoles of epicalyx spathulate, with stellate and glandular trichomes on adaxial surface ( Fig. 3C, a unique feature in the genus), petals obdeltoid ( Fig. 1N ), column conic ( Fig. 1Q ), and mericarps with simple and glandular trichomes ( Fig. 3D ).

Peltaea rupestris resembles P. riedelii as referred in the diagnosis especially in the shape of leaf blades and other characters cited above. However, their geographic distribuition is allopatric, P. rupestris being restricted to Minas Gerais state in Southeast of Brazil, and P. riedelli is widely distributed. Peltaea rupestris shares with P. stellata and P. chiquitana the mericarps with glandular trichomes, an unusual character in the genus. In addition, P. rupestris is endemic to Minas Gerais state and P. stellata endemic to Tocantins state, and P. chiquitana is found in Bolivia.

Additional specimens examined (Paratypes):— BRAZIL: Minas Gerais: Joaquim Felício, Serra do Cabral , Morro da Onça , 6 August 1985 (fl), M.G.L. Wanderley et al. 811 ( SP); ibidem, Serra do Cabral , 950–1000 m, 14 April 1996 (fl, fr), G. Hatschbach et al. 72043 ( CTES, MBM); ibidem, 14 April 1996 (fl, fr), G. Hatschbach et al. s. n. ( CTES 263399 ); ibidem, próximo ao rio Embaiassaia , 22 September 2005 (fl), G. Hatschbach & E. Barbosa 79467 ( MBM); ibidem, próximo ao Armazém da Lage , 18 November 1997 (fl), G. Hatschbach et al. 67226 ( MBM); ibidem, Serra do Cabral , 14 April 1996 (fl), G. Hatschbach et al. 64681 ( CTES, MBM); Corinto, Beltrão , 13 March 1997 (fl, fr), G. Hatschbach et al. 66173 ( CTES, MBM); Buenópolis, entre a Rod. BR-135 e Curimataí , 9 June 2004 (fl), G. Hatschbach et al. 77632 ( CTES, MBM) .

Figures

FIGURE 1. A–H. Peltaea brasiliana (based in A.J. Fernandes-Júnior 286). A. Flowering branch; B. Details of branch indument; C) Bracteoles of epicalyx. D) Inner surface of calyx. E) Staminal tube. F) Petal. G) Mericarp. H) Seed. I–Q. Peltaea rupestris (based in L.R. Lima et al. 119). I. Flowering branch. J. Details of branch indument. K. Bracteoles of epicalyx. L. Inner surface of calyx. M. Staminal tube. N. Petal. O. Mericarp. P. Seed. Q. Column. R–B’. Peltaea stellata (based in F.C.A. Oliveira et al. 2000). R. Flowering branch. S. Indument of adaxial leaf surface. T. Indument of abaxial leaf surface. U. Bracteoles of epicalyx, abaxial surface view. V. Bracteoles of epicalyx, adaxial surface view. W. Inner surface of calyx and details of indument. X. Staminal tube. Y. Petal. Z. Mericarp. A’. Seed and indument detail. B’. Column.

FIGURE 3. Scanning electron micrographs of Peltaea species. Peltaea brasiliana (based in A.J. Fernandes-Júnior 286). A. Seeds, outside view, simple and biradiate trichomes. Peltaea rupestris (based in L.R. Lima et al. 119). B. Branch with sparse stellate trichomes and longitudinal line of simple and stellate trichomes. C. Bracteoles of epicalyx: adaxial surface with stellate and glandular trichomes. D. Mericarp, dorsal side, simple and glandular trichomes. Peltaea stellata (based in F.C.A. Oliveira et al. 2000). E. Inner surface of calyx with simple, stellate and glandular trichomes. F–H. Mericarp, dorsal side. F. Biradiate and glandular trichomes. G. Simple, biradiate and stellate trichomes. H. Stellate trichome.

FIGURE 4. Geographical distribution of Peltaea brasiliana (●), Peltaea rupestris (Ì) and Peltaea stellata (▲).