Everyone knows Silver Birch.
Its bark stands out from the other native trees. Smooth and creamy-silvery grey-white when young, mature trees have darker, crusted bark coming up from the base, creating patterned panels and ridges of the remaining pale bark.
Lovers of the Silver Birch have named it the "Lady of the Woods" for generations*, as noted by Samuel Coleridge in his poem:
"I pass forth into light--I find myself
Beneath a weeping birch (most beautiful
Of forest trees, the Lady of the Woods)..."
But Silver Birch is a unisex tree, with male and female flowers on one plant.
You could call Birch the Lady Man of the Woods
Being male or female is "normal" for animals. I'm saying normal here to mean that us Mammals do it. Many types of Fish, Amphibians and Reptiles pursue other options.
With flowering plants, normal mostly means to be a full Hermaphrodite.
A typical flower - a rose, say - has frilly little male bits called stamens, which are composed of delicate, perishable filaments with soft anthers on the end that release the pollen.
In the heart of the same flower, the much larger female parts contain the waiting eggs, with an opening for the pollen grains in amongst the lacy male stamens, often rising erect above them on a thicker pillar called the stigma.
Birch, like Alder, is a Monoecious Hermaphrodite, which means that each individual tree has separate male and female flowers, or catkins, in their cases. A catkin is a type of flower, also called an ament.
For a plant to be a girl or a boy, a Lord or a Lady, it has to be Dioecious, which means that each plant makes only male or female flowers.
Male plants of a Dioecious species are called androecious, females are gynoecious.
To help you remember all of that, I wrote this poem for you:
The ecious bit is from the Greek: it means a house,
Mono is one, Di is two,
Andro's a boy, like Andrew,
Gyno is a girl, as in Gynecocratic Supremacist,
And Silver Birch trees are a pretty forest dwelling Monoecious Hermaphrodite.
*Except in Lincolnshire, where they call it the Ribbon tree.
People from Lincolnshire are called Yellerbellies. They are proud of it, though no one is really sure why - please comment if you have an idea.