Along the Ottawa River, by Carol L. Douglas. You don't need to be able to identify species at 200 paces, but you do need to be able to recognize how trees differ.
Trees, clouds and rocks are all frequently abused in the same way: the oblivious painter never thinks about their individual characteristics but paints them interchangeably. That's a mistake.
There is a major division in the forest world between conifers (the trees with needles) and broadleaf trees. Most, but not all, conifers are evergreens; the biggest exception being the larches (tamaracks), which turn a delicious yellow-gold in autumn. Which are dominant in your landscape? Even in the Pine Tree State, the distribution of conifers to deciduous trees is about 50/50.
Old Bones, by Carol L. Douglas
Pines have fewer branches than spruces or firs, and their branches grow in circular whorls on the trunk. As they age, they develop an open, jagged canopy. Spruce branches grow in an upturned direction; as youngsters, they look the most like ‘Christmas trees’. In their dotage, they turn a fine, weathered figure to the wind. Firs have wide lower branches and a downcast mien. Notably, their cones point upward.
Most scenes will include a variety of canopy shapes.
(Something that puzzles me: why do people find ancient trees more beautiful than their offspring, but prefer looking at young people over the elderly?)
Conifers are most easily identified by their needles. Pine needles grow in clusters of two, (red pines), three (yellow pines), or five (white pines), held onto the stem with a tiny papery wrapper. Spruce needles are short, stiff and grow individually from twigs. Fir needles are soft and flat. Cedars have flat, scale-like leaves and stringy bark. Junipers (including, confusingly, the Eastern Red Cedar) have berrylike, bluish cones on the tips of their shoots.
Along Kiwassa Lake, by Carol L. Douglas
Many people can identify the common broadleaf trees by their leaves, and I’ve included a chart to help you. The important part for the painter, however, is to see the differences in color. Silver maples have a lovely grey-silver color. Sycamores are garbed in military-fatigue green. Black spruces are dark while Eastern White Pines are fair and soft in their coloring.
This is why I discourage my students from using tube greens and encourage them, instead, to mix a matrix of green colors.
Basic broadleaf leaves.
Too often, we painters ignore young trees, something I tried to rectify (with varying success) last season. Young trees often look radically different from their aged ancestors, but they have a beauty of their own.
To be a convincing painter, you don’t need to memorize the species of trees, but you do need to learn to distinguish between them. Any plausible landscape will contain a variety of them, with different bark, branch structures, and leaf colors.
Baby black spruce and pines, by Carol L. Douglas