Date Published: February 15, 2018
Publisher: Public Library of Science
Author(s): Shabir A. Rather, Shweta Subramaniam, Shagun Danda, Arun K. Pandey, William Oki Wong.
Two new species of Fabaceae-Papilionoideae are described and illustrated. Crotalaria suffruticosa from Karul Ghat region of Maharashtra is morphologically close to C. albida and C. epunctata. C. multibracteata from Panhala region of Maharashtra resembles C. vestita. C. suffruticosa differs from C. albida and C. epunctata in its habit, leaf, inflorescence, callosity, keel type, stigma, style morphology and number of seeds/pod. To test if the new species differ from their morphologically most similar species, we measured various traits and performed a Principal Component Analysis (PCA). This analysis shows that the new species differs from similar species in gross morphology for several diagnostic traits and showed correlations between the variables or distance among groups and estimated the contribution of each character. Phylogenetic analyses were also conducted based on nuclear (ITS) and plastid (matK) markers. The analyses revealed nucleotide differences between the new species and their close allies attributing to their distinctiveness. A map and key including all species of Crotalaria from Maharashtra state are provided. Conservation status of the two new species have also been assessed.
The Crotalarieae (Benth.) Hutch., (Fabaceae) is the largest tribe in the genistoid alliance (containing 51% of genistoid legumes) and comprises 16 genera and 1204 species [1–5]. More than half of the diversity of the tribe belongs to the genus Crotalaria L., with 702 species [6–7]. Recent molecular work has provided profound insights into generic and specific relationships and better understanding of the group in the tribe Crotalarieae and the genus Crotalaria, thereby establishing the monophyly of the genus [3, 5–6, 8]. An infrageneric classification of Crotalaria was attempted by Le Roux et al. , based on molecular phylogenetic data, which brought significant advances in the understanding of the infrageneric classification, redefined and complemented the previous classification given by Polhill in 1982 . In India, the revisionary work on the genus Crotalaria was undertaken by Ansari  to which further data was incorporated by Subramaniam et al. . The genus Crotalaria is distributed in tropical and sub-tropical regions of the world. The species of Crotalaria exhibits great diversity of habit and ecological preferences. The genus chiefly colonizes open grasslands and forest edges. There are both annual and perennial species, the habit including prostrate or erect herbs, under-shrubs, robust shrubs and rarely trees (e.g., C. agatiflora Schweinf. ex Engl.) [8–9].