A revision of Trigonella sect. Ellipticae (Fabaceae) in Iran M. Ranjbar, R. Karamian, Z. Hajmoradi and M. R. Joharchi M. Ranjbar (ranjbar@basu.ac.ir), R. Karamian and Z. Hajmoradi, Dept of Biology, Herbarium division, Bu-Ali Sina Univ., PO Box 65175/4161, Hamedan, Iran. – M. R. Joharchi, Herbarium of Ferdowsi, Univ. of Mashhad, Iran. In this paper a key, descriptions and new results are provided for Trigonella sect. Ellipticae occuring within the area covered by the flora of Iran. Trigonella sect. Ellipticae comprises perennial herbs, becoming woody at the base, with standard as long as keel and pods glabrous or rarely covered with gray dense and appressed hairs. Trigonella lasiocarpa Ranjbar & Hajmoradi, T. binaloudensis Ranjbar & Karamian, T. stipitata Ranjbar & Joharchi and T. torbatejamensis Ranjbar are described and illustrated as new species based on habit and pollen morphology. Te relationships between the new species and their closest relatives are discussed. Te pollen morphology of 26 specimens belonging to 11 species was studied with light and electron microscopy and discussed in the context of existing hypotheses on the systematic relationships within T. sect. Ellipticae. In addition, T. heratensis Rech. f. and T. adscendens Aphan. & Gontsch. are reported as new records for Iran. Te tribe Trifolieae in the family Fabaceae includes 6 genera: Trigonella, Medicago, Trifolium, Melilotus, Parochetus and Ononis (Heyn 1981, Lock and Simpson 1991, Mabberely 1997). Te tribe, as proposed by Berchtold and Presl (1820), is characterized by having trifoliate leaves and stipules adnate to the petioles. Following the progression of modern tools in taxonomy, numerous taxonomic changes and rearrange- ments have been proposed in these genera. Trigonella L. is one of the largest genera in the tribe Trifolieae and comprises about 135 species widely distributed in dry regions around the east Mediterranean, west Asia, south Europe, north and south Africa, with only one species growing in south Australia (Townsend and Guest 1974, Polhill and Raven 1981, Kawashty et al. 1998). Trigonella species are annual or perennial herbs with pinnately trifoliate leaves, often emitting an odour, and like other grain legumes, are important in food and medicine production (Chopra et al. 1956, Girardon et al. 1989, Balodi and Rao 1991, Bhatti et al. 1996, Dangi et al. 2004). In ‘Flora Iranica’, the genus was represented by 58 annual and perennial species referred to 12 sections (Rechinger 1984). Many of the perennials are endemic to Iran and belong to T. sect. Ellipticae. Te leaves, stems and pods in most of the species of T. sect. Ellipticae are glabrous or sparsely hairy, the hairs are not much variable in length and the flowers of all species have a yellow or violet colour. Trigonella lasiocarpa is the only member of the section that is densely covered with white hairs. Te hairs (up to 0.5 mm long) are found on the leaves and calyx surfaces. Trigonella binaloudensis is the only member of the section in Iran which has exclusively bi-coloured flowers. Studies on the pollen grains of the family Fabaceae have dealt mainly with the description of the pollen of certain genera or sometimes tribes (e.g. Clarke and Kupicha 1976, Ferguson and Skvarla 1981, Ferguson 1990, Ferguson and Stirton 1993, Diez and Ferguson 1994, Hughes 1997). Investigations on pollen morphology (Small et al. 1981) and pollen–ovule patterns (Small 1986) performed in order to resolve relationships within and between the genera Medicago and Trigonella have failed to find rigorous diagnos- tic characters (Bena 2001). In this paper four new species, T. lasiocarpa Ranjbar & Hajmoradi, T. binaloudensis Ranjbar & Karamian, T. stipitata Ranjbar & Joharchi and T. torbatejamensis Ranjbar, are described and two new records, T. heratensis Rech. f. and T. adscendens Aphan. & Gontsch., are reported from Iran and compared with their closest relatives using morphology and pollen micromorphology based on recent botanical col- lections by the staff of the herbarium of Ferdowsi, Univ. of Mashhad (FUMH). Te new species have been compared with known species during the first and second author’s vis- its to the herbaria W and WU in 2005 and 2007. Material and methods Pollen morphology For light microscopy (LM), pollen samples were obtained from herbarium specimens of the Bu-Ali Sina Univ. her- barium or directly collected in the field, prepared using the standard method described by Erdtman (1960), and docu- mented by voucher specimens (Table 1). Ten, they were mounted on unstained glycerin jelly and observed with a Nikon type-2 microscope. Measurements were based on Nordic Journal of Botany 30: 17–35, 2012 doi: 10.1111/j.1756-1051.2009.00171.x, © 2012 Te Authors. Nordic Journal of Botany © 2012 Nordic Society Oikos Subject Editor: Arne Strid. Accepted 27 April 2009 17