Taxonomic revision of Neotropical Murdannia Royle (Commelinaceae)

Abstract

This study provides a taxonomic revision for the Neotropical species of the genus Murdannia. Six species are recognized as native, including a new species and a new combination, while two Asian species are recognized as invasive. We present an identification key, a table summarizing the morphologic differences among the species, a new synonym, six lectotypifications, a distribution map, and descriptions, comments and photographic plates for each species. We also provide comments on the morphology of the Neotropical species of Murdannia, comparing them with the Paleotropical species, and a discussion of inflorescence architecture in the genus as a whole.

Morphological phylogeny of Tradescantia L. (Commelinaceae) sheds light on a new infrageneric classification for the genus and novelties on the systematics of subtribe Tradescantiinae

“…The monospecific T. sect. Rhoeo is recovered as an independent lineage at the base of the Campelia clade, sister to two clades. One of these clades represents a monophyletic T. sect. Cymbispatha ( sensu Pellegrini et al 2016), herein called the T. commelinoides group, being well-supported (BS= 76; BI= 5) and characterized by: herbaceous stems (Character 4, homoplastic); distichously-alternate leaves (Character 6, homoplastic), with membranous leaf-blades (Character 10, homoplastic), and acute apex (Character 20, homoplastic); equal (Character 40, homoplastic), basally fused (Character 42), not overlapping cincinni bracts (Character 44, homoplastic); keeled dorsal sepal (Character 56, homoplastic), chartaceous sepals (Character 57, homoplastic), rotund to rhomboid petals (Character 61, homoplastic), and pistil shorter than the stamens (Character 86, homoplastic) (Figs 3, 4A). Tradescantia sect. Cymbispatha is recovered as sister to a small, well-supported (BS= 79; BI= 4) clade, herein called the T. zebrina group, composed by T. sect. Campelia, T. sect. Corinna, and T. sect. Zebrina.…”

“…Indeed, a great deal of variation is observed in the family as a whole, with some patterns characteristic or synapomorphic to several taxonomic ranks (Brückner 1930; Handlos 1975; Hunt 1983; Faden 1991, 1998; Faden and Hunt 1991; Pellegrini et al 2016; Pellegrini and Faden 2017). The androecium morphology of Commelinaceae is known to vary regarding the: (1) symmetry of the androecium as a whole; (2) number of stamens; (3) fertility of the stamens; (4) similarity between the inner and outer whorl of stamens; (5) similarity within each whorl of stamens; (6) connation with the corolla; (7) filament connation; (8) position, curvature and torsion of the filaments; (9) pubescence of the filaments; (10) insertion of the anthers; (11) morphology of the connectives; (12) morphology of the anther sacs; (13) relative position of the anther sacs; (15) dehiscence of the anther sacs; and (16) fertility of the pollen grains (Faden 1998; Evans et al 2000, 2003; pers.…”

“…Pellegrini et al 2016; Pellegrini and Faden 2017). For instance, subfamily Cartonematoideae was characterized based on the absence of several morphological features present in subfamily Commelinoideae, such as raphide-canals and glandular microhairs (Faden and Hunt 1991).…”

“…11.2). Thus, I was able to select the names that better characterize the clade, also avoiding names that might increase the existing taxonomic confusion in Tradescantia (Pellegrini et al 2016). Finally, I provide an identification key to the subgenera, and characterize each one of them, also providing the approximate number of species and names accepted in each one of them.…”

Recircumscription and taxonomic revision of Siderasis, with comments on the systematics of subtribe Dichorisandrinae (Commelinaceae)

“…in Streptoliriinae (Thitimetharoch 2004); (2) appendaged seeds are recorded for at least two separate lineages in tribe Commelineae (i.e. some species of Commelina L. and Murdannia Royle; Pellegrini et al 2016); (3) truly fleshy fruits are known only from Palisota Rchb. ex Endl.…”