Gentianales


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Gentianales

[‚jen·chə′nā·lēz]
(botany)
A family of dicotyledonous plants in the subclass Asteridae having well-developed internal phloem and opposite, simple, mostly entire leaves.
References in periodicals archive ?
Note the isolated position of the Menyanthaceae, confirming its exclusion from the Gentianales and possibly the Solanales and Scrophulariales as well.
The Gentianales, as modeled here, contains approximately 8% of all known extant angiosperm genera and approximately 5.
Consensus is that the Menyanthaceae be excluded from the Gentianales.
Thorne (1992) likewise maintains the Saccifoliaceae as a separate family, having at first (Thorne, 1983) suggested it form a subfamily, the Saccifolioideae, under the Gentianales.
Within the Gentianales the circumscription of the Loganiaceae has been problematic for a long time, but due to the recent reassessment of existing morphological and chemical data, as interpreted with (Bremer & Struwe, 1992) and without (Jensen, 1992) cladistics, a consensus is slowly being reached on how the family should be defined.
Tribe Buddlejeae (= Family Buddlejaceae): The overall consensus is that this tribe should be given family status, the Buddlejaceae, and that its true affinities are with the Scrophulariales and not the Gentianales (Airy Shaw, 1985; Cronquist, 1988; Dahlgren, 1983; Takhtajan, 1983; Wagenitz, 1977).
Data suggest that Desfontainia Ruiz & Pavon may be abridging taxon between the Cornanae and Loganiaceae and these authors see merits in including it, at family level, in either the Gentianales as defined in this paper or Cornanae sensu Thorne ([is approximately equal to]Rosales of Cronquist or Saxifragales of Takhtajan).
The one rather noticeable exception to the almost universal consensus regarding the nearest relatives of the Plocospermateae seems to be Jensen (1992), who suggests, on chemical grounds, that this monotypic tribe be placed outside the Gentianales near the families Scrophulariaceae or Oleaceae; but this does not concur with strong morphological data.
Although there is no consensus for its exact placement, agreement seems to be that the tribe Retzieae/family Retziaceae should not be placed within the Gentianales.
By consensus the Buddlejaceae and Retziaceae are excluded from the Gentianales altogether.
The Loganiaceae (which is primarily woody and generally less specialized for insect pollination) would seem to be near the central base from which the order Gentianales arose.
Phylogenctic relationships within the Gentianales based on ndhF and rbcL sequences, with particular reference to the Loganiaceae.