THE AMERICAN BOTANIST 109 



Spring Flowers in Autumn. — The flowers of early 

 spring' are almost without exception produced by perennial 

 species that store up food in their stems or other underground 

 parts over winter. They are thus able to spring into bloom 

 without waiting to put up stem and leaves as the summer 

 flowers are obliged to do. Many of the summer flowers are 

 perennials, also, but if they store food at all, this is not suf- 

 ficient to carry them through the period of flower and fruit 

 formation. The spring flowers, also, usually have a remark- 

 ably short period of vegetative activity. By the time the 

 forest trees have fully spread their leaves, all traces of many 

 of them have entirely disappeared above ground, yet in this 

 short time they have accumulated enough food to carry them 

 through another season. Their vegetative habits give them a 

 great advantage over other plants and permit them to live in 

 the forests where summer flowering species would find it dif- 

 ficult to grow. Additional interest is lent to this group from 

 the fact that specimens are frequently found in bloom in 

 autumn. The flowering is rarely, if ever, general, but here and 

 there in the woods and fields one comes upon specimens. Cer- 

 tain seasons seem to affect the result. A dry, hot summer, 

 followed by a cool, moist autumn is usually most productive 

 of the phenomena. It is well known that heat and cold have 

 similar effects upon plants. In forcing flowers to bloom out 

 of season the florist finds that dipping the dormant plants in 

 boiling water has the same effect as freezing them. They 

 develop much sooner under such treatment. After a hot sum- 

 mer some of the spring flowers act as if spring had come again. 

 It may be well to remember that certain plants, the madonna 

 lily for example, have two growing seasons, one following 

 winter, when it blooms, and one following summer when it 

 merely puts out a new set of leaves. The bird-foot violet not 

 only has two seasons of growth, but has a different shaped 

 leaf for each season. All our violets show a disposition to 

 bloom twice a vear. 



