7602 Gentianella Moench
- Moench, Methodus: 482 (1794) nom. cons..
Notes: Many grassland species of Gentianella show a pattern of both regional and seasonal races. Seasonal races are found in managed meadows and pastures. The same pattern is shown by several other hemi-parasitic grassland genera, e.g., Euphrasia, Odontites, and Rhinanthus in Orobanchaceae. There may be no simple way to handle infraspecific taxonomy and nomenclature in these taxa. The seasonal races may be ecotypical varieties selected for under different land-use regimes. They differ in anthesis and fruiting before or after the mowing or grazing, strongly influencing the branching pattern. The early flowering races - often with autumnal germination - develop rapidly and have few and often long internodes (longer than the leaves), little branching, and few flowers. The late flowering races develop more slowly and have the opposite features. Branching pattern is associated with leaf shape and ratio between internodes and leaf length and this variation is parallelled in several species. These characters must be strongly adaptive and their value in taxonomic recognition may be debatable. In a recent study of the G. amarella aggregate (Winfield et al. 2003), the authors found the seasonal races to be local adaptation, more closely related genetically to the other seasonal 'race' in the same site than to the same 'race' in another site, e.g., polyphyletic ecotypes. If the results from this study are repeated in other groups, the value of the seasonal races as taxa will be debatable. The regional races differ more from each other - in less or not adaptive characters - and they can be treated as eco-geographical races if they are sufficiently well differentiated. Below, we accept regional races but comment only on the seasonal ones, also because these do not play any role in the Arctic, mainly north of agriculture.
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Source: Osi at Wikispecies
