In one case, at least, the author has also observed that a plant which has been barren of seed at first changed into a seed-bearing plant the following year. Similar changes in the sexuality of strawberries have been observed under certain conditions. These facts may explain, in a measure, the difficulty experienced in raising permanently sterile asparagus plants.
_Asparagus acutifolius._--A native of Southern Europe and Northern Africa. It has a fleshy rootstock, hard, wiry, brown stems, five to seven feet high, with rigid branches three to six inches long, thickly closed, with tufts of gray-green, hair-like, rigid leaves, which in exposed situations are almost spinous. Flowers yellow, a quarter of an inch in diameter, fragrant. The young sprouts are tender, and, when cooked, of a peculiar aromatic flavor. In their native home they are used like the cultivated kind.
_A. aphyllus._--Indigenous to Greece, where the young shoots are commonly used as food, especially during Lent.
Although but one species of edible asparagus has found its way into general cultivation, many varieties and strains are recognized.
Up to within a comparatively recent period it was thought that there existed only one distinct kind, or variety, of asparagus. As late as 1869 so keen an observer as Peter Henderson believed that "the asparagus of our gardens is confined to only one variety, and the so-called giant can be made gigantic or otherwise, just as we will it, and the purple top variety will become a green top whenever the composition of the soil is not of the kind to develop the purple, and _vice versa_. All practical gardeners know how different soils and climates change the appearance of the same variety. Seeds of cabbage taken from the same bag and sown at the same time, but planted out in soils of light sandy loam, heavy clayey loam, and peat or leaf-mold, will show such marked differences when at maturity as easily to be pronounced different sorts. This, no doubt, is the reason why the multitude of varieties of all vegetables, when planted side by side to test them, are so wonderfully reduced in number."
But after inspecting an acre of ordinary asparagus and an acre of Abraham Van Siclen's Colossal--which was afterward introduced as Conover's Colossal--at Jamaica, L. I., N. Y., Mr. Henderson wrote: "A thorough inspection of the roots of each lot proved that they were of the same age when planted. The soil was next examined, and found to be as near the same as could be, yet these two beds of asparagus showed a difference that no longer left me a shadow of a doubt of their being entirely different varieties."