Austinia montana (Moric.) Buril & Simões 2014

Buril, Maria Teresa, Simões, Ana Rita, Carine, Mark & Alves, Marccus, 2014, Austinia, a new genus of Convolvulaceae from Brazil, Phytotaxa 186 (5), pp. 254-260 : 256-259

Austinia montana (Moric.) Buril & Simões comb. nov. ( Figs. 1–2 ).

Basionym: Ipomoea montana Moricand (1837: 44) . Jacquemontia montana (Moric.) Meisner in Martius (1869: 304). Thyella montana (Moric.) House (1906: 314) . Lectotype (designated here):— BRAZIL. Prov. Bahiensis, Montagnes de la Jacobina, Blanchet 2533 (G!, isolectotypes F!, K!, P!).

Ipomoea serrata Choisy (1837: 135) . Jacquemontia serrata (Choisy) Meisner in Martius (1869: 304). Thyella serrata (Choisy) House (1906: 314) . 1906. Lectotype (designated here):— BRAZIL. Prov. Minarum, Martius 1937 (M!). syn. nov.

Jacquemontia serrata var. major Meisner in Martius (1869: 305). Lectotype (designated here):— BRAZIL. Prov. Bahiensis, Martius s.n. (G!; isolectotype: P!). syn. nov.

Jacquemontia serrata var. minor Meisner in Martius (1869: 305). Lectotype (designated here):— BRAZIL. Prov. Bahiensis, Blanchet 3159 (G!; isolectotype: P!). syn. nov.

Jacquemontia serrata var. triloba Meisner in Martius (1869: 305). Lectotype (designated here):— BRAZIL. Pernambuco, Houllet s.n. (G!). syn. nov.

Jacquemontia serrata var. obtusata Meisner in Martius (1869: 305). Jacquemontia obtusata Hallier f. (1893: 542). TYPE:— BRAZIL. Prov. Bahiensis, Blanchet 3395 (holotype G!; isotype P!). syn. nov.

Climbing or, rarely, prostate shrubs; stems pubescent to velutinous, trichomes simple. Leaf blades 1.5–15 × 1– 14 cm, usually ovate, sometimes oblong, oblanceolate, elliptic, orbicular, quadrate or rotund, entire or 3–5-lobed; margins often serrate or dentate, rarely serrulate or entire; base truncate to cuneate; apex acute to mucronate; generally velutinous or, rarely, pubescent, the trichomes whitish in vivo, sometimes golden when dried, simple; petioles 0.2–1.5 cm long, densely pubescent. Inflorescences axillary capituliform cymes; peduncles 2.5–17 cm long, longer or shorter than the subtending leaves, densely pubescent; pedicels ca. 1–2 mm; outer bracts broadly ovate to lanceolate, 1–1.7 × 0.5–1.2 cm, the base truncate, the apex acute or mucronate, rarely retuse, abaxially velutinous, adaxially pubescent; the second set of bracts from the base of the peduncle enclosing the inflorescence, narrowly ovate to elliptic, longer than the sepals, velutinous. Sepals 5, persistent, unequal, the 2 outer 5–1.4 × 2–7 mm, obovate to elliptic, with truncate bases and acute apices, velutinous, the middle one ca. 1 mm shorter and slightly asymmetric, the 2 inner ones 4–1.2 × 2–6 mm, narrowly ovate to oblong, pubescent. Corolla bright yellow, widely funnelform, 1.5–2.5 cm long, 1.5–3 cm diam., glabrous. Stamens subequal, filaments 5–8 mm long, pubescent at the base, anthers ca. 2.5 mm long, twisted at dehiscence; pollen grains 3-zonocolpate, spherical to prolate, perforate, spinulate. Style 0.5–1 cm long, equalling the longer stamens; stigmatic lobes 2, globose, ca. 0.5 mm diam.; ovary 2-locular, 4-ovulate, 4-lobate; 5- lobate nectariferous disc present. Fruit a spherical capsule, ca. 0.5 cm diam., enclosed by the sepals and inflorescence bracts, brown, glabrous, 4-seeded, dehiscing by 4 valves. Seeds ca. 4 × 3 mm, brown, glabrous, smooth.

Habitat, Distribution and Conservation: — Austinia montana occurs in eastern Brazil, from the state of Piauí south to the state of Rio de Janeiro, in areas of Caatinga, Campos Rupestres, Cerrado and Atlantic forest. It is common in open and shrubby vegetation, where it usually grows on rock outcrops. In the Atlantic forest , it grows in coastal sandy areas, which are locally called “Tabuleiros”. This vegetation consists of dense, low, often prostrate shrubs (Map 1) .

MAP 1: Map showing distribution of Austinia montana (Moric.) Buril & Simões , with panel on right showing locations of four leaf types.

Etymology: —The genus is named in honour of Dr. Daniel Austin for his great contribution to our knowledge of Convolvulaceae from the American continent.

Variation within Austinia : —When transferring Ipomoea montana and I. serrata to Jacquemontia, Meisner (1969) distinguished the species by the morphology of the outer bracts (ovate on the first and lanceolate on the second one). He also described several varieties of J. serrata based mainly on leaf characters. There is considerable variation in leaf shape, size and indumentum in Austinia . Specimens from Tabuleiro areas in the Atlantic forest have small entire or trilobate leaves with the indument varying from pubescent to velutinous. Populations in the Espinhaço Range, in Bahia, have larger leaves with a denser indumentum, but the shape varies from entire and oblong to 5-lobed and broadly ovate. Specimens from Caatinga areas from Ceará to Pernambuco have leaves intermediate in size and indument density (Map 1). Overall, however, the slight differences in bract shape do not warrant segregation into two species and whilst extreme leaf forms can be readily distinguished, the variation in leaf traits is continuous with intermediates precluding the recognition of distinct taxa ( Fig. 2 ). Consequently, we propose the recognition of a single species, with I. serrata and all of its varieties considered synonyms of Austinia montana .

Selected analysed material: — BRAZIL. Alagoas: Olho D’água do Casado , estrada de acesso, 11 August 2000, Silva 1651 ( RB!, SP!) . Bahia: Andaraí, road to Mucugê , 22 June 1996, Luceño 293 ( UFP!) ; Barra da Estiva, Serra do Sincorá , 23 March 1980, Harley 20850 ( K!, NY!) ; Feira de Santana , retorno da BR 116 , 7 September 1983, Noblick 2728 ( HUEFS!, SP!) ; Igatu , 24 June 2009, Buril & Rodrigues 384 ( BM!, HUEFS!, NY!, UFP!) ; Jacobina, Serra de Jacobina , 28 February 1974, Harley 16564 ( IPA!, NY!, RB!) ; Lençóis , 14 February 1994, Harley et al. 14042 ( K!, SPF!) ; Maraú , 9 May 1966, Belém 2120 ( NY!, UB!) ; 2 March 2001, Matos-Silva 4341 ( HUEFS!) ; Morro do Chapéu , 10 November 2007, Roque 1682 ( MAC!) ; Mucugê , 4 February 1974, Harley 15900 ( IPA!, HUEFS!, K!) ; Palmeiras, Morro do Pai Inácio , 21 May 1980, Harley 22249 ( IPA!, K!, NY!) ; Pindobaçu, Serra do Poço Pelado , 16 May 2009, Buril 344 ( BM!, HUEFS!, UFP!) . Ceará: Beberibe, Fazenda Santo , 2 July 2007, Loiola 1160 ( HUFRN!) ; Caucaia , 5 June 1996, Castro 22 ( EAC!) ; Icapuí , APA de Ponta Grossa, 8 November 2000, Ximenes 19 ( EAC!) ; Mauriti, Umburanas , 13 May 2009, Buril 306 ( BM!, HVASF!, UFP!) . Espírito Santo: Guarapari, Setiba , 11 June 1985, Pereira 47 ( SP!, VIES!) ; São Mateus, Reserva Biológica de Sooretama , 15 May 1977, Martinelli 2220 ( RB!) . Minas Gerais: Almenara, Fazenda Limoeiro , 29 February 2004, Lombardi 5690 ( SP!) . Paraíba: Conde, Praia de Coqueirinho , 28 July 2001, Barros 3060 ( SP!) . Pernambuco: Buíque, Parque Nacional Vale do Catimbau , 11 November 2003, Souza 396 ( HST!, HUEFS!) . Piauí: Baixa do Barreiro , PARNA de 7 cidades, 7 May 2000, M. Alencar 918 ( SP!) . Rio de Janeiro: Rio de Janeiro , restinga de Cabo Frio, 19 September 1968, Sucre 3727 ( RB!) . Rio Grande do Norte: Mossoró, Estrada do Tibau , 31 August 1984, Ataide 573 ( IPA!, RB!) ; Natal, Parque Estadual das Dunas de Natal , 21 June 2007, Loiola 1061 ( HUFRN!) . Sergipe: Itabaiana, Serra de Itabaiana , 13 June 1986, Viana 1265 ( ASE!) .

Figures

FIGURE 1: Austinia montana (Moric.) Buril & Simões. A. Habit. B. Inflorescence. C. Bracts and bracteoles, from left to right the outermost to the innermost.D. Sepals, from left to right the outermost to the innermost. E. Open flower, F.Anthers, detail after dehiscence. G. Gynoecium. H. Ovary with lobate disc. J. Capsule. Drawn from Buril & Rodrigues 384 (BM, HUEFS, NY, UFP). Drawn by Regina Carvalho.

FIGURE 2: Morphological variation in leaves of Austinia montana (Moric.) Buril & Simões. A. Harley et al. 51512. B. and L. Harley 22249. C. Matos-Silva 4341. D. Harley 14042. E. Luceño 293. F. Belém 2110. G. Harley 20850. H. Harley 26094, J. Viana 1265. K. Buril 306. M. Buril 344. N. Sucre 3727. O. Ximenes 19. Scale bars: 1 cm. Drawn by Regina Carvalho.