Rudgea agresteophila Zappi, J.G. Jardim & Bruniera

Bruniera, Carla P., Zappi, Daniela C. & Groppo, Milton, 2015, Rudgea agresteophila and R. hileiabaiana (Palicoureeae, Rubiaceae): two new species from eastern Bahia, Brazil, Phytotaxa 202 (4), pp. 289-293 : 290

1. Rudgea agresteophila Zappi, J.G. Jardim & Bruniera , sp nov. ( Fig. 1A–D )

Rudgea agresteophila resembles Rudgea vellerea Müller (1881: 208) , from southeastern Brazil, in having flowers with a wide calyx, and differs from this species by the externally glabrous corolla (vs. densely villous in R. vellerea ) and strongly coriaceous, not distinctly veined leaves (vs. chartaceous, distinctly veined leaves).

Type: — BRAZIL. Bahia: Jequié, Anel Rodoviário BR 116/ BA 330, vicinal para fazendas com entrada ca. 10 km do Anel Rodoviário, Fazenda Riachão, ca. 4 km da entrada, 13°46’14’’S, 40°01’18’’W, 588 m, 31 March 2004, fl., L. C. Senra 51 (holotype HUEFS!).

Treelets to trees, to 7 m tall; branches pale greyish, glabrous, corky, slightly compressed, upper internodes 1.5–2.5 cm long, slightly thickened at nodes. Stipules sheathing, 2–3 upper pairs present, interpetiolar portion broadly obovate, 3–7 x 4–8 mm, apex truncate to rounded, dorsally keeled, (sub-)terminal keel 5–8 mm long, with terminal deciduous glandular appendages 1 – 2 mm long. Leaves with petioles (3–)5–11 x 2–3 mm, canaliculate; leaf blades oblanceolate to obovate, 12–19 x 4–9 cm, base acute to cordate, apex obtuse to rounded or sometimes abruptly acuminate, strongly coriaceous, drying yellow-green, shiny above, paler and less shiny beneath, margin thickened, revolute, midrib adaxially sulcate and yellowish, abaxially very prominent; secondary veins (10 –)13–16 on each side of midrib, prominent on both sides, tertiary venation visible on both sides, glabrous; domatia absent. Inflorescence terminal, a compound cyme, 4–6 cm long, 12–15-flowered; peduncle 2.5–3 cm long, branched twice; pedicels 1–5 mm long. Flowers (only in bud) 5-merous, externally glabrous; hypanthium ca. 2 mm long; calyx limb 4 – 6 x 6–8 mm, tube expanded, much wider than hypanthium, reaching ½ of the length of the corolla tube, truncate to irregularly toothed at apex, longitudinally striate; corolla ca. 10 mm long, carnose, white, tube pubescent within at the mouth, lobes not corniculate; filaments ca. 5 mm long, anthers ca. 4 mm long, dorsifixed; nectar disc ca. 1 mm long, depressed centrally; style ca. 6 mm long. Fruit ovoid, 10–16 x 10 mm, calyx remnants tubulose, irregular, ca. 4–6 mm long, crowning the fruit at the apex.

Etymology: — The specific epithet refers to the dry, ecotonal forest that occurs between the eastern, very humid coastal strip of Atlantic Forest and the dryland vegetation known as caatinga. This semi-deciduous forest, often with spiny plants and many lianas, is known as mata-de-cipó or agreste in northeastern Brazil.

Distribution and habitat: — Rudgea agresteophila has a narrow distribution in the state of Bahia, where it was collected only once, in the municipality of Jequié. It grows in the transition between the Atlantic Forest and the dry hinterland, at 500–600 m elevation.

Phenology: — Specimens with flowers and immature fruits were collected in March.

Conservation Status: — Data deficient (DD). There are only two known collections, both from the type locality.

Additional specimen examined (paratype): — BRAZIL. Bahia: Jequié, Anel Rodoviário BR116/ BA 330, vicinal para fazendas com entrada ca. 10 km do Anel Rodoviário, Fazenda Riachão, ca. 4 km da entrada, 13°46’14’’S, 40°01’18’’W, 588 m, 31 March 2004, imm. fr., L.C. Senra s.n. (HUEFS 96517).

Discussion: — This new species is morphologically distinct within the genus, combining thickly coriaceous leaves, flowers with expanded calyx-tube and fruits crowned by tubular calyx remnants to 4–6 mm long. Efforts were directed at recollecting Rudgea agresteophila to provide additional fertile material with open corollas, as well as DNA samples. Collecting such materials would have shed light on the relationships between this very distinct species and its putative allies. The town of Jequié still has native vegetation in its surroundings, but the species could not be found there. At present, the distribution of R. agresteophila is restricted to a single locality, but it is possible that its distribution may extend into other areas with similar ecotonal vegetation.

Figures

FIGURE 1. A–D. Rudgea agresteophila. A. Branch with inflorescence. B. Stipule. C. Detail of inflorescence. D. Fruit. E–J. Rudgea hileiabaiana. E. Branch with inflorescence. F. Stipule. G. Flower bud. H. Flower. I. Fruit. J. Seed, dorsal and ventral view. A, D: Senra s.n. (HUEFS 96517); B, C: Senra 51 (HUEFS); E, G, H: Santos 3882 (SP); F: Fiaschi 1880 (SPF); I: Thomas 11917 (SP), J. Fiaschi 2121 (SPF). Drawn by Maíra Clasen Massarani.