Annals of the Missouri Botanical Garden. Vol. 41: 301-305 (1954)
LADYFINGER AND TOM THUMB, TWO OLD VARIETIES OF POPCORN
Missouri Botanical Garden and Washington University
WILLIAM L. BROWN
Department of Plant Breeding, Pioneer Hi-Bred Corn Company
|1In discussing these two varieties we have used the oldest names in the literature, the more readily since they are appropriate names and since they have been widely used for these varieties at one time or another. Ladyfinger has been very extensively referred to, not only as Tons Thumb but as Australian Hull-less. The latter name, however, seems to have been even more widely applied to varieties which apparently came from crosses between Ladyfinger and some variety with a higher row number. The name Tom Thumb has been applied not only to Ladyfinger but also to various small-eared popcorns, including pointed-kernel types which morphologically are very different from the Tom Thumb herein described.|
Two very different varieties of popcorn, Ladyfinger and Tom Thumb,1 have been extensively confused in agronomic and genetic literature. While the correct naming of popcorn varieties is a matter rather outside the ordinary realm of scientific endeavor, these two varieties have been so frequently used in genetic and breeding experiments, East (1911), White (1917), and Kempton (1926), that it seems worth while to describe and differentiate them. Aside from small kernels and small cobs the two have almost nothing in common. Each represents a morphologically extreme type among the readily available United States varieties of Zea Mays; for that very reason both may be of potential importance in practical breeding programs as maize breeding becomes even more scientifically expert.
A few of the outstanding differences between these two varieties are shown in Table I. Even though the varieties have been confused because both have small ears and small kernels, they are readily distinguishable even by these characters. Ladyfinger has smaller kernels than does Tom Thumb and they are a straw-yellow rather than a butter yellow. The ear of Ladyfinger does indeed suggest a finger, being slender and straight-sided, while the ear of Tom Thumb, though usually even shorter, tapers from the center to both ends, like a miniature barrel.
In growth habit the two varieties are diametrically different. Tom Thumb is the earliest of early varieties and does not grow into a normal plant south of the northernmost tier of states. In most of its characters it is a typical northern flint (Brown and Anderson, 1947). It has one or two ears on the main stalk when grown in southern Minnesota. It tillers readily and the tillers are inferior to the main stalk. The foliage is a yellowish-green and the tassel has few and slender branches. Ladyfinger is the latest variety of any kind of maize in most of the gardens in which it grows. Its growth habit is like that of Oriental Popcorns (Stonor and Anderson, 1949): it develops slowly; its leaves are upright; the internodes are short; it may have 5 to 7 ears on the main stalk. It tillers abundantly and the tillers are subequal to the main stalk in size and appearance (pl. 12, fig. A). The tassel, though small, has many branches and is scarcely exserted from the upper leaves.
TABULATION OF OUTSTANDING DIFFERENCES BETWEEN TOM THUMB AND LADYFINGER POPCORNS
|Season||Very early||Very late|
|Ear shape||Small, barrel-shaped||Small, finger-shaped|
|Kernel color||Deep yellow||Pale yellow|
|Tassel||Few branches; exserted from leaves||Many branches; tassel surrounded by upper leaves|
|Internodes||Few; upper ones elongated||Many; upper internodes very short|
Little is known of the history of either variety though both have been commonly grown under various names and both have been used in popcorn breeding for over fifty years. Eldredge (Eldredge and Lyerly, 1943) described both varieties as among the types of Tom Thumb popcorns which he found when assembling material for his popcorn-breeding program.
Though little is known about the agronomic history of Ladyfinger the facts suggest that it may be one of the oldest varieties of maize. It is strikingly similar to varieties of popcorn obtained from pre-Columbian graves in Chile and Peru. Varieties somewhat resembling it have been obtained from scattered localities in South America and, as mentioned above, it is generally similar to the popcorns collected among the primitive Naga tribes of Assam by Stonor. Though we do not know how or when it reached the United States, we do know that it has been here over a century. A detailed description of it by Ebeneezer Emmons in 1849, leaves no room for doubt that it was this very same variety to which he gave the name of Ladyfinger in his survey of the maize varieties in New York State (p. 265):
"Illinois or Ladyfinger corn. Pale yellow. Ear small, slender, and tapering. Rows 12. Kernels small, pointed, rounded upon the back. It is an unproductive kind, bearing sometimes four ears upon a stalk, but the stalk is from 7 to 8 feet high. It is a late kind ...."
Ladyfinger is a high-quality popcorn. Though small and comparatively flavorless, it is delicate in texture and is almost completely devoid of the roughage which some people find so objectionable in most other popcorns. It is this high quality which has preserved it in spite of its lateness and rather low yield. We have frequently found it being grown by small seedsmen or in home gardens. Inquiry as to where it had been obtained has always produced a similar story. Some friend or relative found it to be of such high quality that it was recommended as being worth while in spite of its lateness. In the few cases where we were able to go back one step farther we learned that the previous grower had himself obtained it in just such a fashion.
Ladyfinger has evidently been used considerably in popcorn breeding. We found the first-generation hybrid between it and Japanese Hull-less types to be high both in quality and yield. Various blends of the two varieties are, or have been, under cultivation but those which we have grown show a strong tendency to revert back to the original Ladyfinger type.
About Tom Thumb we know even less. In its growth habit it is so similar to the early small-eared northern flint varieties such as those grown by the Micmac Indians that it would seem to be either a northern Indian variety or one produced by crossing some other popcorn with one of these varieties.
In our collections are specimen ears, some of them going back to the first decade of the twentieth century from several localities in eastern north America. Modern popcorn breeding has driven it almost out of existence. From Professor Wiggans of Cornell we obtained a very early inbred derived from this variety or one of its hybrids. We were not, however, able to obtain viable seed of the open-pollinated variety until we finally located a stock at the Montreal Botanical Garden where the superintendent, Henri Teuscher, had been growing it for some years. Because of its scientific value this was increased for us by William Landgren of Willmar, Minnesota, and will be generally available for scientific or practical experiments.
EXPLANATION OF PLATE PLATE 12
Fig. A. Above, 6 ears of Tom Thumb; below 6 ears of Ladyfinger. Scale at the right in centimeters.
|Fig. B. Close-up of tassel of Tom Thumb. Line is the same width as those in the background of Ladyfinger illustration.||Fig. C. Typical plant of Ladyfinger. Tracing of leaf blade at the left. Background ruled in lines 25 cm. apart.|