Catolesia monocephala Roque & S.C. Ferreira, 2018

Roque, Nádia, Ferreira, Silvana C., Amorim, Vivian O. & Berg, Cássio Van Den, 2018, A new species of Catolesia (Asteraceae, Eupatorieae) from Chapada Diamantina, Brazil, Phytotaxa 347 (4), pp. 272-278 : 273-277

Catolesia monocephala Roque & S.C. Ferreira , sp. nov.

Type :— BRAZIL. Bahia : Palmeiras, Serra do Esbarrancado, 12° 44 ′ 39.7 ′′ S, 41° 30´24.9´´W, 1421 m alt., 29 September 2015, V. O. Amorim 408 (holotype: ALCB; isotypes: HUEFS, SPF, US). Figs. 1 , 2 .

Shrubs 30 to 50 cm tall, branches vinaceous at the apex, glabrous. Leaves densely spiraled, laminae 1.5–4.5 × 0.1–0.2 cm, aciculate, fleshy, concolor, apex obtuse, margin entire, base truncate, glabrous, sessile. Inflorescence terminal, solitary, exceeding upper stem leaves; capitula discoid, ca. 1 × 0.8 cm, campanulate, pedunculate, peduncle 1.5–5 cm long, 6–11 bracteoles subtending each capitulum, 0.5–10 × 0.5 mm, aciculate, fleshy, green-purplish; phyllaries 32–44, glabrous, outer ones 4–8 mm long, aciculate, apex obtuse, base truncate, fleshy, glabrous, green-purplish, inner ones 4–7 × 1–1.5 mm, spatulate, plane, apex acute, margin entire, base cuneate, weakly ciliate with eglandular moniliform trichomes, purplish; receptacle conical, paleaceous, glabrous; paleae 60–70, 4–5 × 0.8 mm, spatulate, apex acute, flat, margins involute or revolute. Flowers 60–100 per head, corolla roseous to white, corolla 3–4 × 1–1.2 mm, glabrous, corolla lobes 0.5–0.8 × 0.5–0.7 mm, triangular, apex obtuse, mammillate at margins, anthers 1–1.5 mm long, apical anther-appendages as long as wide, oblong, rounded, basal anther thecae rounded, anther-collars cylindrical; style ca. 5 mm long, base cylindrical, not enlarged, glabrous, stylopodium annuliform, style branches ca. 3 mm long, terete filiform, conspicuously short-papillose. Cypselae ca. 2 mm long, 5-ribbed, glabrous or few setulae eglandular on upper; carpopodium decurrent, annular or cylindrical; pappus absent.

Etymology:—The species epithet is related to the solitary capitulum at the apex of the peduncle instead of capitulescence in the other two species of Catolesia .

Phenology:—Flowering time in August and September.

Distribution and Habitat:— Catolesia monocephala has been collected in the Serra do Esbarrancado, municipalities of Mucugê and Palmeiras, in rocky fields vegetation. The species occurs as a small population restricted to a single mountain and is known from only six collections.

Conservation Status:—The species is considered critically endangered (CR) based on the criteria and sub-criteria B1 a,b (i,ii,iii,iv) of IUCN (2001), i.e. fragmented and endemic populations occurring in one conservation unit but threatened by human impact (tourism) and fire during the dry season.

Phylogenetic placement:— Roque et al. (2017) have included sequences of the specimen “ Ferreira et al. 348 ” in their phylogeny (genebank accession numbers: ITS KP901168, trnL-trnF KP901233). This sample was positioned as sister to the other two species of Catolesia . Morphological characters strongly support this specimen as a new species belonging the genus.

Taxonomic comments:— Catolesia is endemic to the rocky fields vegetation in Bahia state. It was described by Hind (2000), who indicated a close relationship to Agrianthus , Arrojadocharis , Bahianthus , Bishopiella , Lasiolaena , Semiria and Stylotrichium based on the many-flowered capitula, (densely) spirally inserted leaves and several species with variously defective pappus. According to this author, Catolesia and Agrianthus are the only genera in this group to possess a paleaceous receptacle but the former can be separated by a set of characters such as glabrous stems (vs. variously pubescent), abscence of leaf secondary venation (vs. prominent), 2-seriate involucre (vs. 3–5 seriate), absent pappus, rarely with minute abortive setae (vs. setae–flattened, rarely absent), respectively. Recently, Amorim & Roque (2017) found a new species of Stylotrichium in which the receptacle is also conical and paleaceous, but this genus is quite distinctive considering the style pubescent below the bifurcation, and pappus absent or short subpaleaceous.

Rivera et al. (2016) clarified the phylogenetic relationships of Brazilian Eupatorieae and have shown that the informal groups cited by Hind (1999a, 2000) are mostly not monophyletic. In the later study by Roque et al. (2017) Catolesia , Bahianthus , Morithamnus and Lapidia were recovered as a highly supported clade composed of loosely branched shrubs of 2 to 4 m high (vs. herb, subshrub or ericoid habit) and capitula with receptacle flat to convex (vs. convex to conical). Currently there is no morphological synapomorphy for the clade but new systematic efforts can assess the characters and their significance in the evolutinary history of these groups.

On the other hand, pappus of bristles (instead of absent or defective pappus in Catolesia ) can be cited as a symplesiomorphy for Lapidia , Morithamnus and Bahianthus . From the latter, Catolesia can be recognized by the sessile leaves (vs. petiolate) and paleacous receptacle (vs. glabrous). Considering the phylogeny in Roque et al. (2017), Catolesia monocephala is sister to the two other species in the genus and shares with Bahianthus the individualized capitula rather than a congested capitulescence similar to a pseudanthium as found in C. mentiens ( Fig. 3 A,B ) and C. huperzioides ( Fig. 3C ). Therefore this a likely symplesiomorphy between this species and Bahianthus , suggesting an ancestral relation based on morphology.

Catolesia monocephala is quite distinctive from the the other species of the genus by the solitary and pedunculate heads at the apex of the branches, leaf laminae aciculate, apex obtuse, receptacle paleae 60–70, flowers 60 to 100 per head and pappus absent ( Fig. 3 ).

Figures

FIGURE 1. Catolesia monocephala Roque & S.C. Ferreira. A. Flowering branch. B. laminae aciculate, fleshy. C. Head. D. Head in longitudinal section showing receptacle conical and paleaceous. E. Flower and palea. F. Palea with margin revolute. G. Apex mammillate of corolla lobes. H. Style with stylopodium annuliform at base. I. Anthers. J. Cypselae 5-ribbed, few trichomes at apex and carpopodium decurrent (drawn from the holotype by Natanael Nascimento dos Santos).

FIGURE 2. Catolesia monocephala Roque & S.C. Ferreira. A. Shrubby habit. B. Leaves sessile, laminae aciculate, fleshy. C. Head terminal and flowers in anthesis (Photographs:A–C: V.O. Amorim).

FIGURE 3. Catolesia mentiens D.J.N. Hind. A. Capitulescence terminal showing heads congested. B. Details of three pedunculated heads. Catolesia huperzioides Roque, H. Rob. & A.A. Conceição. C. Shrub abundantly ramified, leaves scale-like, imbricated, appressed, and capitulescences at the apex of the branches (Photographs:A–B: V.O. Amorim, C. A.A. Conceição).