Nature Bulletin No. 662   January 13, 1962
Forest Preserve District of Cook County
John J. Duffy, President
David H. Thompson, Senior Naturalist

****:PLANT ROSETTES

In winter our landscape is mostly leafless trees silhouetted against the 
sky, and the dead stalks of wildflowers, weeds and tall grasses -- with or 
without a blanket of snow. Some snows lie on the ground for only a few 
days. Others follow one after another and cover the ground with white 
for weeks at a time. Soon the eye begins to hunger for a glimpse of 
something green and growing. Then, in sunny spots where the snow has 
melted or where youngsters have cleared it away, there appear clusters 
of fresh green leaves pressed tight to the soil.

Whether it is a dandelion in the lawn, a pansy in a flower border, or a 
thistle in a vacant lot, such a typical leaf cluster -- called a winter 
rosette -- is a ring of leaves around a short central stem. The leaves are 
narrow at the base, wider toward the tip, and spread flat on the ground 
with little or no overlap. This arrangement gives full exposure to 
sunlight and close contact with the warmer soil beneath. Such plants 
continue to grow, sometimes faster, sometimes slower, even under 
snow, throughout winter.

Each kind of plant seems to have a calendar of its own. There is a time 
for growing tall, a time for flowering, and a time for scattering seed. 
Among those herbaceous plants that live over from one year to the next 
-- biennials and perennials -- the winter rosette is especially suited for 
temperate climates. In its first summer a biennial such as a wild carrot 
or an evening primrose grows a rosette of leaves from a seed. This lives 
over winter, shoots up a tall stalk the next summer, blooms, ripens seed, 
and then the whole plant dies. In many perennials, for example the 
hollyhock and common plantain, the flower stalk dies as the days grow 
shorter but the underground parts and a rosette of green basal leaves 
live on until the following year when, again, they flower and set seed.

In our region the winter rosette habit of growth is scattered through 
many families of flowering plants and over many types of environment. 
Almost all of them are viewed in different ways by different people, 
depending on where they grow and on our personal likes and dislikes. 
By and large, the majority of them thrive in poor soils and in waste 
places where they furnish ground cover and aid in breaking up and 
enriching the soil. With their hardy underground parts they survive 
fires, floods, trampling and grazing.

The rosettes of dandelion, plantain and buckhorn are merely lawn pests 
to most people. However, some of us enjoy a mess of dandelion greens 
in spring. In farmers' pastures, grain fields and hay fields a few of these 
winter rosettes followed by their tall summer stalks are noxious weeds. 
Cattle, sheep and horses refuse to eat spiny thistles and teasel, the fuzzy 
mullein, or the ill-flavored wild carrot also called Queen Anne ' s lace. 
But, on roadside s, old fields and waste places their bold flowers add 
welcome color. In autumn, when dead and brown, they are picked for 
winter bouquets.

Strawberries come from rosettes which are cultivated by the thousands 
of acres. Smaller in size but full of flavor, ripe wild strawberries abound 
in the forest preserves each June. The tender leaf clusters of winter 
cress or yellow rocket make a salad that tastes the same as its near 
relative, the water cress.

Our wildflower season is ushered in by the blooming of the hepatica, 
usually before the last snows of spring. Its delicate white, lavender or 
pale blue flowers on their furry stems push up from a winter rosette of 
three-lobed liver-colored leaves. On the other hand, the blooming 
season is closed, often after autumn snows have begun to fly, by the 
purple flower spikes of a little mint called heal-all which also arise from 
a ring of basal leaves.