Feb. 1907,] 



87 



Edible Products. 



in the home of the race. It is a clover-like plant ; indeed, a field "of it forcibly 

 suggests a luxuriant crop of clover. The stems may attain a height of 1 to 2 feet, 

 or at times of 3 feet but for the most part lie more or less prostrate on the soil. 

 It is the custom in the United States to plant the rows 2| to 3 feet apart, when the 

 branches ultimately meeting have a length of nearly 2 feet. 



The leaf- of Arachis has four leaflets placed in pairs, each attached by a 

 motile organ (pulvinulus) to the common leafstalk; like clover leaflets they exhibit 

 sleep movements, each pair folding together at nightfall and remaining thus until 

 dawn. The flowers, which are pea-like and bright orange-yellow, are produced one 

 at a time from large buds at the bases of the leaves. Their duration is but short, 

 for they wither for the most part on the day of their production. Outside the 

 orange-yellow petals is the yellow-green calyx, rather irregularly divided into the 

 five sepals, and below it the long calyx tube (at times f inch long), which to the eye 

 appears to be a footstalk to the flower. At this period the flower has no peduncle, 

 and the ovary lies within the calyx-tube protected by the bracts in the leaf-axil. 

 It is only after the fertilization of the flower that the true peduncle appears. 



Not all the flowers fruit ; many never advance beyond the blossoming stage, 

 and have been thought to be male flowers. After the fertilization, as the first 

 preparation towards fruit-ripening, the petals and sepals shrivel, while the calyx 

 tube is cut off by a ring at the very base. At this time the true peduncle 

 begins to grow, and turns downwards towards the earth, carrying the remains 

 of calyx and corolla as a cap and appendage over the small ovary. Not until the 

 earth is reached does the swelling of the fruit commence; then the cap just 

 mentioned falls off, the scar which is left by the separation of the style at its base 

 becomes exposed, and the young pod, at first sharp at the end, commences to 

 penetrate the soil. At 1 to 3 inches below the surface, rarely deeper, it ripens in the 

 course of a few weeks into the familiar " earth-nut." The usual number of seeds 

 in a pod is two ; one is not uncommon, three rare, and four to five occur only in a 

 form which, according to Heuze (Plantes industrielles, II. p. 135) is found in Costa 

 Rica. 



Any flower whose ovary fails to reach the ground fails likewise to produce 

 fruit. Correa de Mello (Journ. Linn- Soc. XL, p. 254) records an experiment in which 

 he prevented the flower-stalk from penetrating the earth by interposing an object ; 

 in the attempt to round the obstacle the peduncle grew to 4 or 5 inches long, but 

 failed, and the immature ovary died without enlarging. Fruiting is thus dependent 

 on the effectual burying of the young pod. It is obvious that the flowers of the 

 upper part of the stem stand in a disadvantageous position, for they can less 

 readily bury their pods, nor do many of them appear to make the attempt. When 

 harvest comes the plants may be raised from the ground and stacked to dry in the 

 fields, the nuts hanging on to their stalks among the roots ; then will be seen on 

 the root-fibres little nodules which are transformed rootlets, altered iu internal 

 structure, and of a peculiar use to the plant. Such tubercles are common in 

 the Leguminosae and by possessing the capability of absorbing free atmospheric 

 nitrogen enable the plant to gain this necessary food in a way not open to other 

 orders of the higher plants. They are indicated in many figures of Arachis. 



It has been said (Eriksson, Studier ofver Leguminosernes rotkuolar Lund, 1874) 

 that Arachis lacks these tubercles ; such is not the case. Several observers have 

 mentioned their existence, notably Lecompte (Comptes Reudus Acad. Paris, 119, p. 

 302), and specimens from many parts of the world preserved at Kew may be seen to 

 possess them. That they are formed less readily in some soils than iu others is 

 stated by Andouard (Comptes Rendus Acad. Paris, 117, p. 298), aud may well be the 

 case, 



