Fraxinus

Fraxinus , commonly called ash, is a <a href="/facts/Genus/m8EFjSms">genus</a> of plants in the olive and lilac family, <a href="/facts/Oleaceae/gWDrrrbw">Oleaceae</a>, and comprises 45–65 species of usually medium-to-large <a href="/facts/Tree/HVVn3srN">trees</a>, most of which are <a href="/facts/Deciduous/7jQHVtdd">deciduous</a> trees, although some <a href="/facts/Subtropics/gK0KyFUD">subtropical</a> species are <a href="/facts/Evergreen/bcLptUdV">evergreen</a> trees. The genus is widespread throughout much of Europe, Asia, and North America.
The leaves are <a href="/facts/Opposite_leaves/8xGtgllo">opposite</a> (rarely in <a href="/facts/Whorl_(botany)/dhD4zdUI">whorls</a> of three), and mostly <a href="/facts/Pinnate/1tm6hMyo">pinnately compound</a>, though simple in a few species. The seeds, popularly known as "keys" or "helicopter seeds", are a type of fruit known as a <a href="/facts/Samara_(fruit)/56xvcjMW">samara</a>. Some Fraxinus species are <a href="/facts/Dioecy/jwMHLkuM">dioecious</a>, having male and female flowers on separate plants but sex in ash is expressed as a continuum between male and female individuals, dominated by unisexual trees. With age, ash may change their sexual function from predominantly male and hermaphrodite towards femaleness; if grown as an ornamental and both sexes are present, ashes can cause a considerable litter problem with their seeds.
<a href="/facts/Rowan/JYmRIerW">Rowans</a>, or mountain ashes, have leaves and buds superficially similar to those of true ashes, but belong to the unrelated genus <a href="/facts/Sorbus/oSQgWKa6">Sorbus</a> in the <a href="/facts/Rosaceae/KYrlFdv6">rose family</a>.

Fraxinus open-in-new

Fraxinus