ORIGINAL ARTICLE Pollen morphology and detailed sexine of Passiflora subgenus Astrophea (Passifloraceae) Ana C. Mezzonato-Pires 1 • Michaele A. Milward-de-Azevedo 2 • Cla ´udia Barbieri F. Mendonc ¸a 1 • Vania Gonc ¸alves-Esteves 1 Received: 11 February 2015 / Accepted: 15 April 2015 Ó Springer-Verlag Wien 2015 Abstract From the palynological perspective, Passiflora subgen. Astrophea shows itself as a very interesting sub- genus. The main aim of this study is to provide micro- characters that allow the recognition of taxa and the cir- cumscription of the Passiflora subgen. Astrophea. The pollen was acetolyzed, measured, described and illustrated under light microscopy and non-acetolyzed pollen grains were analyzed in scanning electron microscopy. Quantita- tive data were subjected to multivariate analysis. The pollen grains are 6-colporate, 3-endoapertures clearly la- longate, unique for each pair of ectoaperture; tectate, par- tially tectate or semitectate exine, when present, muri may be only around the apertures or they may be remaining muri, continuous or discontinuous, simplicolumellate or duplicolumellate. The results defined four types of pollen, based on sexine, three of which were recognized by mul- tivariate analysis. This study shows the importance of pollen morphology for the taxonomy of group, allowing a reassessment of the subgenus currently established and, hence, a better understanding of the recognized phyloge- netic lineages. Keywords Astrophea Á Exine Á Multivariate analysis Á Passiflora Á Pollen Á Taxonomy Introduction Passifloraceae s.s. has about 17 genera and approximately 630 species (Deginani 1999; Mabberley 1997; Brummitt and Powell 1992; Holm-Nielsen et al. 1988). According to Bernacci et al. (2015), around 150 species and four genera occur in Brazil: Ancistrothyrsus Harms, Dilkea Mast., Mitostemma Mast. and Passiflora L., the last one is the most representative. Feuillet and MacDougal (2003), based on morphological and ecological characters, suggested four subgenera: Astrophea (DC.) Mast., Deidamioides (Harms) Killip, Decaloba (DC.) Rchb. and Passiflora. Muschner et al. (2003), Muschner (2005) and Zamberlan (2007), using phylogenetic analyses based on molecular markers, agreed with Feuillet and MacDougal (2003) except for the fact that they did not only accepted P. subgen. Deidamioides. The results found by Yockteng and Nadot (2003), Hansen (2004) and Hansen et al. (2006), based on molecular phylogeny supports the monophyly of the four subgenera. Yockteng and Nadot (2003), indicate the possibility of recognizing more subgenera, among the 22 proposed by Killip (1938). Passiflora subgen. Astrophea comprises around 60 species distributed in South and Central America, only two species occurring in Central America: P. pittieri Mast. and P. tica Go ´mez-Laur. & L.D.Go ´mez (Ulmer and MacDou- gal 2004). In Brazil, the subgenus is composed by ap- proximately 24 species (Bernacci et al. 2015). The most current classification divides the group into two supersec- tions: Astrophea, with three sections, and Pseudoastrophea (Harms) Feuillet and MacDougal, with two sections and two series (Feuillet and MacDougal 2003). Passiflora subgen. Astrophea species have similarities with typical passiflora, but they have morphological char- acters unique to this subgenus such as the arborescent habit Handling editor: Michael Hesse. & Vania Gonc ¸alves-Esteves esteves.vr@gmail.com 1 Departamento de Bota ˆnica, Universidade Federal do Rio de Janeiro, Museu Nacional, Rio de Janeiro, RJ 20940-040, Brazil 2 Departamento de Cie ˆncias Administrativas e do Ambiente, Instituto de Tre ˆs Rios, Universidade Federal Rural do Rio de Janeiro, Tre ˆs Rios 25802-100, Brazil 123 Plant Syst Evol DOI 10.1007/s00606-015-1223-0