Comanthera retroflexa L.R.Parra & Giul., 2011

Parra, Lara Regina & Giulietti, Ana Maria, 2011, Two new species of Comanthera (Eriocaulaceae) from Bahia, Brazil, Phytotaxa 27, pp. 1-7 : 4-6

Comanthera retroflexa L.R.Parra & Giul. , sp. nov. ( Figs. 2A–O )

Species insignis a congeneribus receptaculo capitulorum post anthesin convexo-conico et bracteis involucralibus retroflexis distinguenda, sed ex affinitate C. mucugensis (Giul.) L.R.Parra & Giul. subsp. mucugensis et C. giuliettiae L.R.Parra a speciebus ambabus foliis caniculatis, ciliatis et utrinque pilosis et a C. mucugensi subsp. mucugensi capitulis manifeste minoribus (5–7 × 10–12 non 6–15 × 18 –20 mm) differt.

Type:— BRAZIL. Bahia: Mucugê, side of road near Andaraí, ca. 2 km from the town, 1000 m, 16 December 1984, Giulietti et al. CFCR 7012 (holotype SPF!, isotypes K!, SPF!) .

Plants 25–35 cm tall. Stem ca. 2 × 1 cm (including the persistent leaf bases), erect, branched or not, branches ca. 2 cm long, sparsely pilose or glabrous. Leaves 3–6 cm × 1.5–2.0 mm, spirally arranged, erect to deflexed, linear with the apex obtuse to rotund, chartaceous, canaliculate becoming plane later, abaxial surface with thickened veins, abaxial and adaxial surfaces densely hirsute, with patent, white, filamentous trichomes, becoming glabrescent, margins sparsely ciliate, cilia formed by adpressed malpighiaceous and few filamentous, patent trichomes; leaf base expanded, 3–4 mm wide, persisting after abscission of the blade, membranous, margins ciliate, abaxial and adaxial surfaces sparsely hirsute, later becoming glabrescent. Spathes 3–4 cm long, entirely membranous, apex lacerate, densely adpressed-pilose with malpighiaceous trichomes and some patent to subadpressed filamentous trichomes, later glabrescent. Scapes 18–32 cm long, erect, densely pubescent, with subadpressed filamentous and rarely also adpressed malpighiaceous trichomes, later becoming glabrescent. Capitulum 5–7 × 10–12 mm, campanulate, radiate or hemispherical, in fruit becoming convex-conical, receptacle densely hairy with filamentous trichomes, these curled at the apex and ca. 1.5 mm long. Involucral bracts in ca. 8 series, surpassing the flowers by ca. 2 mm in young capitulum and reflexed in mature capitulum; bracts of the outer series coloured light brown to cream, ovate, apex acuminate, densely pilose on the abaxial surface; bracts progressively changing towards the inner series to white, elliptic, apex obtuse, and surface glabrous; bracts of the innermost series obovate, apex rotund. Floral bracts absent. Staminate flowers 2.5–3.0 mm long, including pedicels of 0.8–1.0 mm; sepals 1.5–2.0 mm long, united from base up to a third or half of their length, concave, elliptic with apex acute or obovate with apex obtuse, hyaline and membranous, base opaque-whitish and thicker; anthophore present; petals 1.5–2.0 mm long, united up to a third or half of their length, obovate to spathulate, apex obtuse, hyaline and membranous, base opaquewhitish and thicker; pistillode ca. 0.5 mm long. Pistillate flowers 3.0– 3.5 mm long including pedicels of 0.4– 0.5 mm at anthesis, pedicels elongating up to 1,5 mm in fruit during seed dispersal phase; sepals 1.5–2.0 mm long, imbricate, concave, ovate to elliptic, apex acuminate, hyaline and membranous; petals 2.8–3.0 mm long, hyaline and membranous, ciliate above the middle with abaxial surface pilose, lobes with rotund apices; styles united ca. 0.2 mm long, stigmatic and nectariferous portions both inserted at apex, stigmatic portion ca. 2 mm long, nectariferous portion ca. 0.8 mm long.

Distribution and habitat: —So far only known from the “campos rupestres” vegetation on sandy soils, in the environs of Mucugê, Bahia state, Northeastern Brazil, especially in the area close to the Rio Cumbuca. Populations are small with few plants, or even isolated individuals.

Etymology: —The specific epithet refers to the reflexed involucral bracts when capitula are mature.

Conservation status: —This species is presently known only from a small area nearby the Rio Cumbucas in Mucugê Municipality in Bahia. The total area of occupancy is less than 500 km 2. Therefore, the species is here considered as Endangered A3c; B2ab(iii) ( IUCN 2001). Recently few plants were plotted in the Mucugê Municipality Park and have been very carefully cared of.

Comanthera retroflexa is morphologically similar to Comanthera mucugensis subsp. mucugensis , and C. giuliettiae L.R.Parra (in Parra et al. 2010). All three are endemic to the rocky outcrops (campos rupestres) of Bahia state and grow sympatrically in the Mucugê Municipal Park. The three species possess similarly shaped capitula and involucral bracts. Comanthera retroflexa , however, has unique features, easily recognized in the field: after anthesis, the hemispherical capitula become globose with the involucral bracts reflexing and becoming obscured. Also, the leaves are canaliculate, ciliate, and densely pilose on both surfaces, with patent filamentous trichomes.

Additional specimens examined (paratypes): — BRAZIL. Bahia: Mucugê, Mucugê–Andarai road, km 2, 12º59’S 41º 21’ W, 870 m, 26 February 1989, Cavalcanti et al. 340 ( NY, SPF); close to the confluence of the Mucugê and Cumbuca rivers, 12º59’S 41º 21’ W, 970 m, 3 January 1997, Bautista et al. UMS 78 ( HUEFS); Area of Sustainable Management , Rio Piabinha , 12º59’S 41º 20’ W, 930 m, 12 January 1997, Conceição et al. UMS 188 ( HUEFS); Trilha dos rios Piabinha e Tibourtino , 12º 59’ S 41º 20’ W, 934 m, 8 August 2007, Harley et al. 55641 ( HUEFS) .

Figures

FIGURE 2. Comanthera retroflexa. A. Habit, showing immature and mature capitula. B. Leaf with thickened veins just on the abaxial surface. C. Filamentous trichomes of leaves. D. Malpighiaceous and filamentous cilia of leaves. E. Malpighiaceous trichomes of leaves. F. Malpighiaceous and filamentous trichomes of scapes. G. Capitulum showing shape, indumentums, and apex of the external involucral bracts. H. Staminate flower with base of sepals opaque-whitish and thicker. I. Sepals of the staminate flower (adaxial surface). J. Staminate flower with sepals removed showing petals with base opaque-whitish and thicker. K. Adaxial surface of one petal of the staminate flower. L. Pistillate flower. M. Adaxial surface of sepals of pistillate flower. N. Pistillate flower at anthesis with sepals removed, showing pedicel (a) and anthophore (b). O. Fruit and remains of pistillate flower at seed dispersal phase with sepals and petals removed, showing elongated pedicel (a), anthophore (b), and seed (c). Giulietti et al. CFCR 7012 (SPF).