Praxelis macrocarpa V. Abreu & R. Esteves, 2017

Abreu, Vanessa Holanda Righetti De & Esteves, Roberto Lourenço, 2017, A new species of the Cerrado in Brazil, Phytotaxa 303 (1), pp. 77-83 : 78-82

Praxelis macrocarpa V. Abreu & R. Esteves , sp. nov. ( Figures 1A–F , 2D–F , 3C–G )

Type: — BRASIL. Distrito Federal: Brasília , 16 April 1963, J.M. Pires, N.T. Silva & R. Souza 9.123 (holotype UB; isotype RB) .

Praxelis capillaris valde proxima, a qua capitulis longioribus (8–10 vs. 6–7 mm), involucri phyllis persistentibus (non caducis) sed etiam seriebus numerosioribus (6–8 vs. 3–4) differt.

Perennial herbs up to 50 cm tall; without xylopodium; branches erect, cylindrical, striated and glabrescent. Leaves verticillate, sessile; blade membranous; 15–65 mm long; linear; sharp in two edges; margins entire and revolute; glabrescent on both sides and uninervate. Inflorescence terminal, isolated capitula, with long stems and glabrescent; capitula with 23–26 flowers. Involucres ca. 8–10 mm long; cylindrical; involucral bracts arranged in 6–8 gradually decreasing series, persistent, outer ovate, inner lanceolate; apex eroded in all. Flowers with purple corolla, ca. 6–7 mm long, one lobed longer and papillose corolla inner surface; style branches subulate and papillose; apical anther appendage approximately equal in length and width, obtuse; anther collar balusterform. Cypsela 3–3.5 mm long; 5- ribbed.

Distribution: — Brazil (Midwest: Distrito Federal, Goiás; Southeast: Minas Gerais).

Phytogeographic area: —Cerrado.

Comments: — Praxelis macrocarpa is a new species very similar to P. capillaris ( Candolle 1836: 134) Schultz-Bipontinus (1866: 254) . The two species can be distinguished by the following characters: Involucral bracts persistent, capitula larger (8–10 mm long) with 6–8 series of involucral bracts in P. macrocarpa , whereas in P. capillaris involucral bracts are deciduous, capitula smaller (6–8 mm long) with 3–4 series of involucral bracts ( Fig. 2A–C ). Besides, the size of flowers, fruits and styles is twice greater in P. macrocarpa ( Fig. 3F ) (. 1).

Other material examined (paratypes): — BRASIL. DISTRITO FEDERAL: Brasília, s/d, Heringer, E. P. 10.452 (UB); Brasília, 29/05/1965, D. Sucre 507 (RB); Brasília, 02/05/2007, Clarissa Gouveia Fontes 170 (CEN/RB); Planaltina, 12/05/1981, S. P. Almeida 867 (UB); Sobradinho, 27/04/2008, Correia , C. A. S. 220 (UB); Sobradinho, 27/04/2008, Correia , C. A. S. 222 (UB). MINAS GERAIS: Diamantina, 19/03/1970, H. S. Irwin et al. 27.923 (RB/ UB); Diamantina, 10/04/1973, William R. Anderson 8.574 (RB/UB); Diamantina, 18/05/2008, F. N. A. Mello et al. 297 (ALCB/HUFU); Diamantina, 13/4/2012, Quaresma, A. S. 377 Cota , M. M. T. (ALCB); Santana do Riacho, Serra do Cipó, 03/06/1976, G. Martinelli 866 (RB); Serro, 08/04/2010, F. N. Costa, C. O. Andrino, I. M. Franco & M. P. Tannure 1.267 (ALCB/DIA); Serro, 13/04/2012, Quaresma, A. S. 396 & Cota , M. M. T. (HUEFS). GOIÁS: Alto Paraíso de Goiás, Chapada dos Veadeiros, 23/05/1975, G. Hatschbach 36.735 (HB/MBM); Alto Paraíso de Goiás, Chapada dos Veadeiros, 15/05/1986, Toledo, C. B. et al. 124 (MBM); Alto Paraíso de Goiás, Chapada dos Veadeiros, 25/03/2011, Bringel, J. B. & Moreira, H. J. C. 701 (UB); Brasilândia, Vale São Gerônimo, 02/04/1970, Mitzi R. Ferreira 155 (UB); Formosa, Córrego Itaquera, 02/05/1966, H. S. Irwin, R. Souza & R. Reis dos Santos 15.525 (UB); Niquelândia, 13/04/1996, R. C. Mendonça, R. Marquete, M. L. Fonseca & F. C. A. Oliveira 2463 (RB); Niquelândia, 22/07/2007, M. M. Saavedra et al. 466 (RB); Pirenópolis, 10/07/2006, P. G. Delprete 9.908, T. C. Lousa & A. Francener (RB); Pirineus, 04/06/1971, Rizzo 6.363 (RB); Pirenópolis, 18/07/2007, R. C. Forzza 4.491, R. F. Monteiro, S. S. Saavedra, R. Moura & M. G. Avelar (RB); Serra do Itabirito, 13/06/1978, J. Badini s/n (RB); Serra dos Pirineus, 26/05/1968, E. Onishi, G. M. Barroso & W. Mais 91 (RB/UB); Serra dos Pirineus, 14/05/1973, William R. Anderson 10.272 (RB/UB); Serra Dourada, s/d, A. Rizzo 4.186 (RB); Serra Grande, 10/04/1978, José S. Absás 180 (RB).

Figures

FIGURE 1. Praxelis macrocarpa sp. nov. A. leaf stem. B. capitulum. C. corolla. D. anther. E. style branches. F. cypsela.

FIGURE 2. Size comparisons. Praxelis capillaris A. flower. B. style branches. C. fruit. P. macrocarpa sp. nov. D. flower. E. style branches. F. fruit.

FIGURE 3. Praxelis macrocarpa. A. Polar view of pollen grain—optical cross-section with three apertures (LM). B. Equatorial view of pollen grain—general view (LM). C. Flower—detail of the corolla lobed longer and papillose inner surface (arrow) (SEM). D. Cypsela— detail of the ribs (arrow) (SEM). E. Fruit—detail of the carpopodium showing enlarged basal row of cells (SEM). Praxelis macrocarpa and P. capillaris. F. Comparision of fruit size: bigger fruits—P. macrocarpa; smaller fruit—P. capillaris (SEM). Praxelis macrocarpa. G. Floral disk of the cypsela (arrow) (SEM).