Of all the propensities of plants, none seem more strange than their different periods of blossoming. Some produce their flowers in the winter, or very first dawnings of spring; many when the spring is established; some at midsummer, and some not till autumn. When we see the helleborus fœtidus and helleborus niger blowing at Christmas, the helleborus hyemalis in January, and the helleborus viridis as soon as ever it emerges out of the ground, we do not wonder, because they are kindred plants that we expect should keep pace the one with the other; but other congenerous vegetables differ so widely in their time of flowering, that we cannot but admire. I shall only instance at present in the crocus sativus, the vernal and the autumnal crocus, which have such an affinity, that the best botanists only make them varieties of the same genus, of which there is only one species, not being able to discern any difference in the corolla, or in the internal structure. Yet the vernal crocus expands its flowers by the beginning of March at farthest, and often in very rigorous weather; and cannot be retarded but by some violence offered; while the autumnal (the saffron) defies the influence of the spring and summer, and will not blow till most plants begin to fade and run to seed. This circumstance is one of the wonders of the creation, little noticed because a common occurrence; yet ought not to be overlooked on account of its being familiar, since it would be as difficult to be explained as the most stupendous phenomenon in nature.
"Say, what impels, amidst surrounding snow
Congeal'd, the crocus, flamy bud to glow?
Say, what retards, amidst the summer's blaze,
Th autumnal bulb, till pale, declining days?
The God of Seasons; whose pervading power
Controls the sun, or sheds the fleecy shower:
He bids each flower His quickening word obey,
Or to each lingering bloom enjoins delay."
