MONOCOTYLEDONS: LILIACEM. 659 



the grasses, etc. The gramineae, while belonging to the class 

 monocotyledons, are less closely allied to the other families of 

 the class than these families are to each other. For this reason 

 they are regarded as a very natural group. 



SUGGESTIONS FOR THE STUDY OF THE CORN. 



1151. The corn (Zea mays). The corn or wheat plant may be studied 

 as an alternate for the oat plant. 



The corn plant. Describe the entire plant; the underground roots; 

 the aerial roots in the case of mature- plants; the nodes and internodes of 

 the stem; the leaves. Determine the arrangement of the leaves; the parts 

 of the leaf (blade, sheath; is there a ligule, a membranous appendage at 

 the junction of the blade and sheath, present?). Sketch a leaf showing 

 all the parts. Sketch an entire plant to show details. (See Chapter X 

 for structure of seed, and germination.) 



The staminate inflorescence (the "tassel") forms a terminal panicle 

 on the stem, composed of several spikes which branch from the axis. 

 Note the numerous spikelets on each spike. Determine the number of 

 spikelets at each joint of the rachis (axis of the spike). Separate the 

 parts of a spikelet, and sketch to show the parts of a flower as in the 

 oat shown in figs. 545 and 546. Make a diagram to show the ground plan 

 of the flower. 



The pistillate inflorescence (the ear of corn). This occurs in the axil 

 of the leaves at the joints of the stem. The spikes of each leaf-axil are 

 grown together into a thickened axis ("cob"), forming the "ear " of corn 

 which is covered by the numerous leaf -like bracts ("husks") arising from 

 its base. The styles, each attached to the ovary, emerge from between the 

 ends of the bracts in a silky tuft. 



Sketch a cross-section of an ear showing the arrangement of the ovaries 

 or grains of corn on the axis (cob). Remove some of the ovules (or grains 

 of mature corn) and note the scale-like bracts at the base of each. (In 

 some varieties of corn these scale-like bracts are larger and enclose the 

 grain, as in the oat or barley. 



Material. Entire corn plants at maturity (may be preserved dry) ; 

 young "ears "of corn at time the silk is formed (maybe preserved in alco- 

 hol or dry); the "tassel," at the time of flowering (some of the material 

 should be preserved in alcohol or formalin); ripe ears of corn with the 

 "husks" (dry). 



1152. Lesson III. The sedge family (Cyperaceae). Carez. As an ex- 

 ample of the sedges a species of the genus carex may be studied. If plants 



