GENERA OF GRASSES OF THE UNITED STATES. 
283 
described species from Mexico is a perennial with simple culms and 
creeping rhizomes. A form which is supposed to be the original 
E. mexicana is cultivated occasionally in our Southern States, where 
it is known as teosinte (fig. 171). This is a tall, stout grass, usually 
branching at the base and forming large clumps. The tassel is like 
that of corn, and the fascicles of spikes, inclosed in husks with the 
long styles or silk hanging from the apex, bear a superficial resem- 
blance to the ears of corn. Teosinte is cultivated chiefly for soiling. 
It has sometimes been called Reana luxurians Durieu. 
143. Zea L., maize, Indian corn. 
Spikelets unisexual; staminate spikelets 2-flowered, in pairs, on 
one side of a continuous rachis, one nearly sessile, the other pedicel- 
late; glumes membranaceous, acute; lemma and palea hyaline; 
pistillate spikelets sessile, in pairs, consisting of one fertile floret 
and one sterile floret, the latter sometimes developed as a second 
fertile floret; glumes broad, rounded or emarginate at apex; sterile 
lemma similar to the fertile, the palea present; style very long and 
slender, stigmatic along both sides well toward the base. 
A tall annual grass, with broad, conspicuously distichous blades, 
monoecious inflorescences, the staminate flowers in spikelike racemes, 
these numerous, forming large spreading panicles (tassels) terminat- 
ing the stems, the pistillate inflorescence in the axils of the leaves, 
the spikelets in 8 to 16 or even as many as 30 rows on a thickened, 
almost woody axis (cob), the whole inclosed in numerous large 
foliaceous bracts (husks), the long styles (silk) protruding from the 
top as a silky mass of threads. In the common varieties of corn the 
floral bracts are much shorter than the kernel and remain on the cob 
when the kernels are shelled. 1 Species one. 
Type species : Zea mays L. 
Zea L., Sp. PI. 971, 1753; Gen. PI., ed. 5, 419. 1754. Zea mays is the 
only species described. 
Mays Tourn., in Gaertn. Fruct. and Sem. 1 : 6, pi. 1. 1788. The single species, 
M. zea Gaertn., is the same as Zea mays L. 
Mayzea Raf., Med. Fl. 2 : 241. 1830. Two species included. Zea mays L., on 
which the first species, M. cerealis, is based, is taken as the type. 
In the United States Zea mays L. (figs. 172, 173) is usually called 
corn; in Europe and sometimes in America, especially in literature, 
it is called maize. Corn is one of the important economic plants of 
the world, being cultivated for food for man and domestic animals 
and for forage. It originated 2 in America, probably on the Mexican 
Plateau, and was cultivated from prehistoric times by the early 
1 For note on the structure of the maize oar as indicated in Zea-Euchlaena hybrids, see 
Collins, Journ. Agr. Res. 17: 127-135. 1919. 
2 For a note on the origin of maize, see Collins, Journ. Washington Acad. Sci. 2: 5?0 
1912. 
