Illustration of a typical salicoid tooth, the yellow area showing the expanding leaf vein and glandular seta.Populus trichocarpa leaf margin showing a salicoid tooth. The brownish-yellow area in the axil of the tooth is the glandular seta.
The Salicaceae are the willow family of
flowering plants. The traditional family (Salicaceae sensu stricto) included the willows, poplars, aspens, and cottonwoods. Genetic studies summarized by the
Angiosperm Phylogeny Group (APG) have greatly expanded the circumscription of the family to contain 56 genera and about 1220 species, including the tropical
Scyphostegiaceae and many of the former
Flacourtiaceae.[4][5][6]
In the
Cronquist system, the Salicaceae were assigned to their own order, Salicales, and contained three genera, Salix, Populus, and Chosenia (now a synonym of Salix). Recognized to be closely related to the
Violaceae and
Passifloraceae, the family is placed by the APG in the order
Malpighiales.
Under the new circumscription, most members of the family are trees or shrubs that have
simple leaves with
alternate arrangement, and temperate members are usually
deciduous. Most members have serrate or dentate
leaf margins, and many of those that have such toothed margins exhibit salicoid teeth, a salicoid tooth being one in which a
vein enters the tooth, expands, and terminates at or near the apex, near which are spherical and glandular protuberances called setae. Sometimes the glands will deflate and appear
torus (doughnut) shaped. Some members of the family exhibit violoid or theoid teeth, characters along with presence of an
aril and introrse anther dehiscence that are sometimes used to split the family into three families, Salicaceae sensu medio, Samydaceae, and Scyphostegiaceae.[7][8] Members of the family often have flowers which are reduced and inconspicuous, and all have
ovaries that are superior or half-inferior with
parietal placentation.[9]
Genera by subfamily and tribe
Salicaceae are divided into three subfamilies, with Salicoideae further divided into seven tribes.[3][10][11] Several of these tribes are not monophyletic and await further revision.[4]
^
abChase, Mark W.; Sue Zmarzty; M. Dolores Lledó; Kenneth J. Wurdack; Susan M. Swensen; Michael F. Fay (2002). "When in doubt, put it in Flacourtiaceae: a molecular phylogenetic analysis based on plastid rbcL DNA sequences". Kew Bulletin. 57 (1): 141–181.
Bibcode:
2002KewBu..57..141C.
doi:
10.2307/4110825.
JSTOR4110825.
^Alford, Mac; Dement, Angela (2015). "Irenodendron, a new genus of Samydaceae from South America". Journal of the Botanical Research Institute of Texas. 9 (2): 331–334.