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Ratzeburgiinae Hook.f., 1896

1076345

BIBLIO
 
NOTES
Taxonomie : D'après Welker et al. (2020) "Generic limits in the Rottboelliinae and Ratzeburgiinae are famously complex, with morphological characters intergrading between species and genera; many species have names in several genera. Veldkamp et al. (1986) described the group as “a botanical black hole (…) the smaller and larger genera around the complex spiral down into making its mass even greater and its circumference even more difficult to envisage.” His solution was to place species formerly assigned to Coelorachis Brongn., Hackelochloa, Heteropholis, Ratzeburgia, and Rottboellia in Mnesithea, although this suggestion has not been widely followed (see, e.g., Davidse et al., 1994; Barkworth et al., 2003; Arthan et al., 2016). All members of this group have unawned spikelets, with the sessile one generally sunken into the inflorescence axis, the glumes indurate, the pedicellate spikelet often reduced or lacking, and the pedicel sometimes entirely fused with the inflorescence axis (Clayton, 1973). Given the complex phylogeny of the awnless genera, it is unlikely that any of these characters are uniquely derived or diagnostic, since they are shared with Rottboellia s.s., which is unrelated, and many of the characters also appear in Tripsacinae and Rhytachninae." De fait les analyses moléculaires confirment que dans cette tribu les contours traditionnels de nombreux genres devront être revus. Une révision globale ne pourra sans doute pas être atteinte sans un échantillonnage taxonomique bien plus important.

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