Pavonia exasperata Grings & Boldrini., 2012

Grings, Martin & Boldrini, Ilsi Iob, 2012, Two new species of Pavonia section Lebretonia subsection Hastifoliae (Malvaceae: Malvoideae) from southern Brazil, Phytotaxa 39, pp. 38-46 : 44

Pavonia exasperata Grings & Boldrini. sp. nov.

( Figure 2 & 3 E–I )

Affinis Pavoniae friesii, sed ab ea mericarpiis majoribus, apiculatis et 2 aut 3-tuberculiis lateralibus acutis ambobus lateribus nervo medio, foliis basilaribus interdum lobatis differt.

Type:— BRAZIL. Rio Grande do Sul: near “Pedra do Segredo”, 26 abr. 2009, M. Grings & P. Brack 659 (holotype ICN!, isotypes CTES!, NY!). Subshrubs up to 0.8 m tall; stems covered with stellate trichomes, more dense in younger stems; sometimes with glandular trichomes, more dense in younger stems. Leaf blades subtriangular, triangular, ovate-triangular or suborbicular, sometimes with basal leaves slightly 3-5 lobed, 1.5– 6.5 × 0.8–3.9 cm, sagittate, hastate or subcordate, apex acute or subobtuse, margin crenate-serrate, ciliate, 5– 7-nerved, adaxial surface with sparse stellate trichomes, with sparse simple trichomes, seldom with sparse glandular trichomes, usually in young leaf blades, abaxial surface hoary stellate, usually with a tuft of setose trichomes in the base; petioles 0.8–3.5 cm long, indumentum similar to that of the stems and usually with a tuft of setose trichomes in the apex; stipules subulate 2–6 mm long, with short stellate trichomes and sometimes with setose trichomes in the apex. Flowers solitary in the leaf axils, peduncle 1.0– 3.6 cm long, articulated 3–6 mm beneath the epicalyx, indumentum similar to that of the stems and usually with sparse setose trichomes, more dense in the apex; epicalyx bracts 5, lanceolate or narrowly elliptic, somewhat more narrow in the base, 7–11 × 1–2(–3) mm, stellate-tomentose, sometimes with setose trichomes in the base; calyx 9–10 mm long, with more dense and larger stellate trichomes on the nerves; corolla white to pale-rose, petals 2.4–3.2 × 2.4–3.0 cm, with wine-red veins and claw; staminal column 7–10 mm long; free parts of the stamens 2–4 mm; styles (1–) 3–4 mm longer than the staminal column. Mericarps 4–6 × 3–4 mm, sparsely pubescent, apiculate, prominently carinate, median nerve compressed and with rugosities, tuberculate, with two or three acute and prominent tubercles on each side. Seeds smooth with a tuft of trichomes at opposite ends of the hilum.

Distribution: — Brazil, occurring in the Pampa biome ( IBGE 2004) only in Rio Grande do Sul state ( Figure 4 ).

Phenology: —Flowering specimens have been collected from December to May. This species has cleistogamous flowers, observed in the beginning of November, fruiting from November to May.

Habitat: —Forest edges, scrub and rocky grasslands.

Etymology: —From the Latin “ exasperatus”, meaning rugose, but with prominent tips, referring to the lateral acute tubercles of its mericarps.

Additional specimens examined (paratypes): — BRAZIL. Rio Grande do Sul: Bagé, BR 153, near the limit with Caçapava do Sul, S 30º52'37.3" W 53º36'48.7", 01 November 2009, M. Grings & C. Buzzato 792 ( ICN) , property of Telmo Dias Dutra , 15 January 1992, Girardi-Deiro & Gonçalves 825 ( HAS) ; Caçapava do Sul, BR 290 Km 313, 12 December 2009, M. Grings & R. Paniz 844 ( ICN) , 07 December 1978, A. Krapovickas y C. L. Cristóbal 34213 ( CTES, ICN) , Minas do Camaquá , 06 December 1978, A. Krapovickas y C. L. Cristóbal 34196 ( CTES, ICN) , Guaritas , 12 October 1985, D. B. Falkenberg 2748 ( FLOR) , Passo dos Enforcados , S 30º50'39.2" W 053º36'27.6", 03 November 2010, M. Grings & P. J. Silva Filho 1114 ( ICN) ; Lavras do Sul, Rincão do Inferno, Cabanha Macanudo , S 30º51'38.2" W 53º42'29.7", 06 December 2009, M. Grings, R. Paniz & R. Both 842 ( ICN) , s.l., 10 April 2008, I. I. Boldrini, R. Trevisan & A. Schneider 1498 ( ICN) ; Santana da Boa Vista, Faz. Passo da Chácara , 29 March 1975, A. Sehnem 14597 ( PACA) .

Pavonia exasperata is similar to P. friesii Krapovickas (1977: 318) and P. orientalis Krapovickas (1977: 320) due to its similar narrow epicalyx bracts, usually sagittate leaf blades, and white or pale pink petals with basally vinaceous center and veins. However, P. exasperata differs from these species mainly in its larger mericarps with two to three lateral tubercles at each side of the median nerve. In addition, this species may present slightly lobate leaf blades, especially in basal leaves.

Figures

FIGURE 2. Pavonia exasperata. A. Habit (M. Grings 844, ICN). B. Upper part of the peduncle, epicalyx and calyx. C. Mericarp.

FIGURE 3. A–D. Pavonia salmonea. A. Flower and flower buds. B. Branch with flower, flower buds and immature fruits, emphasizing the epicalyx bracts. C. Branch with leaves, flower and immature fruits. D. Habit and habitat in shrubland; mericarp bottom left. E–I. Pavonia exasperata. E. Branch with flower, immature fruit, and leaf. F. Abaxial face of the corolla, calyx and epicalyx with narrowly elliptic bracts. G–H. Branches with flower buds and fruits. I. Habit and mericarp bottom left.

FIGURE 4. Distribution of Pavonia salmonea and P. exasperata in southern Brazil, in municipalities from Rio Grande do Sul and Santa Catarina states.