l62 



BOTANY OF CROP PLANTS 



the stamens and pistils are borne in separate inflorescences on 

 the same plant (Fig. 57). The staminate 

 tlowers are in a panicle at the top of the 

 stalk; this inflorescence is known as the 

 'Uassel." The pistillate flowers are borne 

 in a spike which is placed in the axil of a 

 leaf lower down on the stem. When mature, 

 the pistillate inflorescence is called the ''ear." 



Staminate Inflorescence ("tassel"). — The 

 rachises of the panicle are long, slender, and 

 spike-hke. One may distinguish between the 

 central and lateral spikes of the panicle. In 

 the central spike (Fig. 58), there are usually 

 from four to eleven rows of spikelets, in pairs. 

 Lateral branches usually have only two rows 

 of spikelets, in pairs. One spikelet of each 

 pair is pedicellate, the other sessile (Fig. 59), 

 or in some cases both may be sessile. The 

 groups of spikelets may overlap. 



Staminate Spikelet. — Each normal stami- 

 nate spikelet bears two flowers, each produc- 

 ing three perfect stamens and a rudimentary 

 pistil (Fig. 60). The glumes are seven- to 

 twelve-nerved, and about equal in size. The 

 lemma is three- to iive-nerved and the palet 

 two-nerved. The two lodicules are fleshy 

 and truncate. The anthers are long. The 

 upper flower of a spikelet matures first; its 

 palet is larger than the lemma, while in the 

 lower flower, the lemma is larger than the 

 palet. 



Pistillate Inflorescence ("ear") General 

 —The ear (Fig. 61) is borne on a short 



Fig. 58.- a 

 single branch of 

 the staminate in- 

 florescence of 

 corn (Zea mays). 



Characteristics. 



