Notes on Echinodorus (Alismataceae)

Systematic consideration of petiole anatomy of species of Echinodorus Richard (Alismataceae) from north-eastern Brazil

“…This variation demonstrates the plasticity of this species-which has a wide distribution from Mexico to the north of Argentina (Haynes and Holm-Nielsen, 1994). Haynes and Holm-Nielsen (1986) have, in fact, proposed that the intermediate forms be considered subspecies. This anatomical variation may also indicate a species complex, as suggested by Fasset (1955) who linked the characteristic of angular petioles to an E. subalatus-E. paniculatus complex.…”

Phylogenetics of Echinodorus (Alismataceae) based on morphological data

“…Therefore, E. aschersonianus is not treated here as a separate species. I have also treated the problematic taxon E. grandiflorus differently from Haynes & Holm‐Nielsen (1986, 1994). Haynes & Holm‐Nielsen (1986, 1994) considered E. grandiflorus as a single species with two subspecies (ssp.…”

“…aureus ), but I have found this classification to be quite unsatisfactory during my field work in South America. In order to test the proposed classification (Haynes & Holm‐Nielsen, 1986) I have split the species into three taxa, E. grandiflorus ssp. aureus , E. grandiflorus ssp.…”

“…Where the herbarium material was incomplete, I have also critically used existing taxonomic literature for character state coding. Several Echinodorus species are very poorly represented in herbaria, and in these cases the data are compiled from the literature (Micheli, 1881; Rataj, 1968, 1969; Haynes & Holm‐Nielsen, 1986, 1994; Haynes & Burkhalter, 1998; Wanke, 1999; Jérémie et al ., 2001). I have also studied digital images of herbarium specimens in cases where herbarium material is sparse, or I have not been able to study any real specimens.…”

“…Rataj, 1975, 1978, 2004) has studied the genus in depth, and in addition to accepting Fasset's (1955) subgenera he divided the genus into 11 sections. Rataj (1975) recognized 47 species, which were too many according to Cook (1978) and Haynes & Holm‐Nielsen (1986, 1994). In their Flora Neotropica treatment, Haynes & Holm‐Nielsen (1994) recognized only 26 species; later one more species was described by Haynes & Burkhalter (1998) and one species of subgenus Helianthium by Jèrèmie et al .…”