Peltaea brasiliana, 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 : 75-78

Peltaea brasiliana A.J.Fernandes-Jr. & G.L.Esteves sp. nov. Type:— BRAZIL. Distrito Federal: Brasília, Park Way , 15°55’10,0’’S, 47°59’01,7’’W, 1000 m elevation, 30 March 2012 (fl, fr), A.J. Fernandes-Júnior 286 (holotype SP!, isotypes CTES!, RB!) . Figures 1A – H , 2A – G , 3A .

This species is easily distinguished of all others of genus in Brazil to present cleistogamous flowers (characteristic referred only to P. steinbachii from Bolivia) and by its foliaceous bracts bearing the red spot at base comprising one third or half of the total length of the bracts, flowers with petals widely spathulate, staminal tube glabrous, the recurved styles and glabrous, and seeds covered by simple and biradiate trichomes.

Shrubs 0.8–1 m tall; branches cylindrical, with stellate trichomes. Stipules 5–6 mm long, subulate; petioles 0.6–1.7 cm long; leaf blades 4.9–9.9 × 1.4–4.1 cm, ovate to broadly elliptical, chartaceous, entire, 5–7-palmativeined, apex acute, base subcordate, margin irregularly serrate, shortly ciliate, both surfaces with stellate trichomes. Flowers cleistogamous, solitary and/or in terminal reduced racemes (capituliform), always subtended by foliaceous bracts; pedicels 1–1.5 mm long; bracts 1.4–2.7 × 1–1.5 cm, ovate-elliptic to ovate, margin ciliate, adaxial surface with long simple and stellate trichomes, reddish and glabrescent at the basal portion, abaxial surface with stellate trichomes; bracteoles of epicalyx 9–10, peltate, with simple and stellate trichomes, ciliate, pedicel 4–5 mm long, internally glabrous, blades 3.5–5 × 1–2 mm, narrowly elliptic to ovate-elliptic; calyx 6–8 mm long, 15-veined, internally with simple and glandular trichomes, externally with stellate trichomes; petals 5.5–6 × 3.5–4 mm, yellowish, with orange spot at the base, widely spathulate; staminal tube 2–2.5 mm long, glabrous, free parts of the stamens distributed in one group at the apical portion of staminal tube; styles recurved, glabrous. Mericarps 4.2–4.5 mm long, muticous, indehiscent, dorsal side slightly nervate, glabrous; column not seen; seeds 2.7–3 mm long, trigonous, with simple and biradiate trichomes.

Distribution and habitat: —Endemic to Distrito Federal, Brazil, growing in grassland fields about 1000 m elevation ( Figure 4 ).

Phenology: —The new species was collected in flower and fruit in March.

Etymology: —The epithet refers to the type locality, the capital of Brazil.

Conservation status: —According to IUCN (2014) criteria, Peltaea brasiliana must be considered Critically Endangered [CR, B2ab (i, ii, iii, iv), c (ii, iii)] because is known from an unprotected area in a single locality.

Notes and taxonomic affinities:— As referred in the diagnosis Peltaea brasiliana is easily recognized in the genus by its foliaceous bracts bearing a red spot at base comprising one third or half of total length of the bracts ( Fig. 2G ), while the others species of genus present a small spot at base; flowers with petals widely spathulate and smaller (5.5–6 × 3.5–4 mm), yellow with an orange spot at base ( Fig. 2 C–D ). Futhermore, this species presents the glabrous staminal tube, the styles recurved ( Fig. 2E ) and glabrous, and seeds covered by simple and biradiate trichomes ( Fig. 3A ). Also it is the only species in Brazil with cleistogamous flowers. This character was described up to now only in Peltaea steinbachii Krapovickas & Cristóbal (1965: 178) , a species endemic to Bolivia that has cleistogamous flowers morphologically similar to those of P. brasiliana regarding the characters of the petals, staminal tube and styles.

Peltaea brasiliana is also similar to P. riedelii ( Gürke 1892: 493) Standley (1916: 113) , a species from Midwest and Northern Brazil, as well as Paraguay, Bolivia, Colombia, Venezuela and Suriname. However, P. brasiliana have branches with only stellate trichomes (vs. simple and stellate trichomes in P. riedelii ), leaf blades 5–7-palmateveined (vs. 3-palmateveined), flowers cleistogamous (vs. chasmogamous), petals widely spathulate (vs. obovate), staminal tube 2–2.5 mm long (vs. 8–12 mm long) and glabrous (vs. with glandular trichomes), free parts of the stamens distributed in one group at the apical portion of the staminal tube (vs. two or three groups along the staminal tube), styles recurved (vs. erect) and glabrous (vs. with glandular trichomes), mericarps indehiscent (vs. dehiscent) and glabrous (vs. with simple trichomes), seeds covered by simple and biradiate trichomes (vs. glabrous).

Additional specimen examined (Paratype):— BRAZIL. Distrito Federal: Brasília, Park Way , 15°55’10,0’’S, 47°59’01,7’’W, 1000 m elevation, 30 March 2012 (fl), A.J. Fernandes-Júnior 287 (SP) .

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 2. A–G. Peltaea brasiliana. A–B. Habitat. C. Flowering branch. D. Staminal tube. E. Recurved styles. F. Fruit. G. Foliaceous bracts. (Photos by A.J. Fernandes-Júnior).

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 (▲).