Paepalanthus capixaba Trovó, Fraga & Sano, 2016

Trovó, Marcelo, Fraga, Claudio Nicoletti De & Sano, Paulo Takeo, 2016, Paepalanthus capixaba (Eriocaulaceae), a new microendemic species from Espírito Santo, Brazil, Phytotaxa 258 (1), pp. 83-88 : 84-86

Paepalanthus capixaba Trovó, Fraga & Sano , sp. nov. ( Figs. 1 , 2 )

Differs from Paepalanthus klotzschianus by possessing an inconspicuous aerial stem, membranaceous to chartaceous leaves, the indument of leaves and spathes not tightly adpressed, sericeous brown scapes, hemispherical to spherical capitula, oblong floral bracts, and sepals and petals with apex not acute.

Type: — BRAZIL. Espírito Santo: Vargem Alta, 18 January 2008, L. Kollmann, A. P. Fontana, C. N. Fraga, M. Simonelli 10303 (holotype RB, isotype MBML).

Herbs usually solitary or rarely forming small clumps, 26−42 cm tall; rhizome present, usually conspicuous, aerial stem ca. 2.5 cm long. Leaves persistent, membranaceous to chartaceous, lanceolate, flat, patent, 7.0−25 × 0.8−2.1 cm, densely sericeous with longitudinally oriented trichomes on both surfaces to loosely matted trichomes on older leaves, margins ciliate, apex acuminate to acute. Spathes 7.0− 14.5 cm long, sericeous, apex ciliate, acute. Scapes ca. 5−34, arranged in a single axillary cohort or in few axillary cohorts, 22−40 cm long, sericeous to rarely glabrescent. Capitula 6−20 mm diam., hemispherical to spherical, white to brownish when old; involucral bracts in 2 to 4 series, cream-colored to golden, deltoid to ovate, flat, ca. 3 mm long, glabrous or abaxially pubescent, margin ciliate toward the apex, apex obtuse to mucronate; receptacle semi-spherical, pubescent. Flowers trimerous, ca. 60 per capitulum, ca. 40 staminate and 20 pistillate; floral bracts oblong, cream-colored to light brown in the upper part, navicular, ca. 2.5 mm long, abaxially pubescent, margin ciliate toward the apex, apex obtuse to mucronate. Staminate flowers ca. 3.5 mm long; pedicel ca. 0.5 mm long; sepals fused at the base, obovate, cream-colored to light brown in the upper part, ca. 3 mm long, abaxially pubescent, margin ciliate toward the apex, apex mucronate; anthophore fleshy, elongate; corolla fused into a tube, hyaline, membranaceous, ca. 2.0 mm long; stamens ca. 2.5 mm long; pistillodes 3, papillose. Pistillate flower ca. 3.5 mm long, pedicel ca. 0.2 mm long; sepals fused at the base, obovate, cream-colored to brown in the upper part, ca. 3 mm long, abaxially pubescent to glabrous, margin ciliate toward the apex, apex obtuse to mucronate; petals obovate to navicular, hyaline, ca. 2.5 mm long, abaxially glabrescent, margin ciliate toward the apex, apex obtuse to rounded; gynoecium ca. 3 mm long, stigmatic branches bifid at the apex, staminodes scale-like. Fruits a loculicidal capsule released by the recurved sepals. Seeds not seen.

Etymology: — Capixaba is the Brazilian local name for the inhabitants of Espírito Santo state. Therefore, the epithet “ capixaba ” refers to the restricted distribution of this species, endemic to Espírito Santo state in Brazil.

Distribution, Habitat, and Conservation:— Paepalanthus capixaba is a microendemic species, as are many Eriocaulaceae . The few known populations of this species grow in full sun in isolated patches of sandy quartzitic soils in the municipality of Vargem Alta, Espírito Santo state ( Fig. 3 ). A noteworthy botanist who collected ca. 1200 specimens in Espírito Santo state is Alexander Curt Brade. In August to September of 1948 and May to June of 1949, Brade committed his field efforts to Vargem Alta, at that time a district of the municipality of Cachoeiro de Itapemirim. In this small area, he collected ca. 300 specimens, from which 19 new species were described (including the species proposed in this paper), nine of them described by Brade himself in five different families ( Brade 1950, 1956, 1957). When describing Tibouchina quartzophila Brade (1956: 219) from Vargem Alta, Brade (1956) pointed out the unique composition of the quartzitic soil and the xeric vegetation of the area, naming the species after this condition. This region is in fact a mosaic of quartzitic patches dominated by shrubby vegetation, inserted within an argillaceous granitic matrix covered by forests. Nowadays, the quartzitic patches are under intense sand mining activity; the surrounding forests are being replaced by pasture or managed forests; and no conservation unit exists in the area. Therefore, in addition to its very restricted distribution, Paepalanthus capixaba is not protected, and is thus considered endangered based on the IUCN criteria, EN: B1ab (i,ii,iii,iv) ( Negrao 2015).

Additional specimens examined: — BRAZIL. Espírito Santo: Vargem Alta ( Cachoeiro de Itapemirim ), 21 August 1948, Brade A. C. 19336 ( RB) ; May 1949, Brade A. C. 19995 ( RB) ; 16 August 1981, Ferreira V. F. 1851 ( SPF) ; 25 May 2009, Kollmann L. et al. 11599 ( MBML, RB) ; 29 April 2015, Goldenberg R. et al. 2138 ( MBML, RB, UPCB) .

Comments:— Paepalanthus capixaba has trimerous flowers organized into single capitula apparently arranged in axillary leaves of isolated rosettes. These features led us to place the species within Paepalanthus ser. Paepalanthus (= Paepalanthus unranked Variabiles Ruhland (1903:123)), a placement that is reinforced by the absence of any further character of the better-defined categories described in Ruhland (1903). Within the group, the species is geographically isolated from the congeneric species, being microendemic to a very isolated area. It has a unique combination of morphological features, reflected in the general habit. It is easily distinguished by the indument of leaves, spathes, and scapes.

Paepalanthus capixaba is morphologically related to Paepalanthus klotzschianus Koernicke (1863: 389) , a species distributed in the sand dunes on the coastal plain vegetation of Rio de Janeiro, Espírito Santo and Bahia states and in the campos nativos, a unique vegetation type from southern Bahia and northern Espirito Santo states ( Peixoto et al. 2008). Both have hairy leaves and approximately the same size of leaves and scapes. However, Paepalanthus capixaba has an inconspicuous aerial stem (vs. an evident aerial stem), membranaceous to chartaceous leaves (vs. rigid leaves), the indument of leaves and spathes not tightly adpressed (vs. tightly adpressed), sericeous brown scapes (vs. reddish glabrous scapes), hemispherical to spherical capitula (vs. discoid to hemispherical), and other small floral features, such as the shape of the floral bract and the apices of sepals and petals. Although both species are recorded from Espírito Santo state, they have allopatric distributions.

The specimen A.P. Fontana 7319 (MBML) collected in Vargem Alta (ES) may be an additional specimen of Paepalanthus capixaba . The specimen matches all morphological features, but has glabrous leaves, spathes, and scapes. The absence of trichomes in this specimen may be an artifact of the drying process or may be an occasional occurrence of specimens growing under the shadow of adjacent trees.

Figures

FIGURE 1. Paepalanthus capixaba Trovó, Fraga & Sano. A. Habit. B. Capitula detail. C. Involucral bract, abaxial surface. D. Floral bract, abaxial surface. E. Pistillate flowers. F. Gynoecium. G. Staminate flower. H. Staminate flower with sepals removed and corolla opened. (Kollmann 10303 RB).

FIGURE 2. Habitat and habit of Paepalanthus capixaba Trovó, Fraga & Sano. A. Overview of the occurrence area in Vargem Alta (ES). B. Habitat detail. C. Rosette detail. D. Habit detail.

FIGURE 3. Distribution map of Paepalanthus capixaba Trovó, Fraga & Sano provided by CNCFlora following the standards described in Martinelli & Moraes (2013).