104 



WEEDS AND USEFUL PLANTS. 



Seeds irregularly ovoid with very thick cotyledons and a straight radicle. 

 Herbs with even-pinnate leaves having elongated stipules adnate to the 

 petiole, the stipe or peduncle of the fertile flowers often elongating sev- 

 eral inches before reaching the earth. (This plant properly belongs to 

 a section of the order not included in our synopsis, and is placed here 

 as a matter of convenience.) 



1. A. HYPOG^J'A, L. Stem procumbent; leaflets obovate, the com- 

 mon petiole not produced into a tendril. 



SUBTERRANEAN ARACHIS. Ground-nut. Pea-nut. 



Fr. L'Arachide. Germ. Die Erd-nuss. Span. Mani. 



Root annual. Stem 9-18 inches long, prostrate or erect, branching, pilose. Leaflets an 

 inch to an inch and a half long, subsessile, minutely mucronate at apex, entire and bor- 

 dered by a pilose nerve; common petioles 1-2 inches long, channelled above, pilose. 

 Sterile floivers, 1 or 2 - 5 or 7, in the upper axils, on long slender pedicels the corolla 

 orange-yellow. 



Cultivated. Native of South America. Fl. July - September. Fr. September -October. 



FIG. 77. The Pea-nut (Arachis hypogsea) , exhibiting the manner in which the ovaries, 

 after flowering, bury themselves in the%arth, where they ripen. 



