SEED-BEARING PLANTS 



495 



veined. The flowers are arranged in s pikelets, and the 

 spikelets in spikes (Fig. 379), racemes, or panicles 1 (Fig. 

 380) . The leafy parts of the flower-clusters 

 are modified as dry scales called glumes. 

 When grain is thrashed the glumes consti- 

 tute the so-called "chaff." There is no 

 perianth. 



430. Palm Family (Palmaceae). The 

 palms are mostly tropical and subtropical. 

 With certain exceptions (e.g., Calamus rat- 

 tan), the stem or caudex is normally un- 

 branched, varies in height with the species, and 

 in most species bears all the foliage near the 

 tip (Figs. 381 and 382). Frequently the old 

 leaves, or their petioles or bases only, re- 

 main attached to the trunk. The leaves, 

 though not morphologically compound, usu- 

 ally have their blades cleft or divided as they 

 mature. The flowers are complete, with three 

 sepals and petals, three to six stamens, and 

 pistil of three carpels. They are monoecious, 

 dioecious, or perfect, according to the species. 



The flowers, intermingled with bracts, oc- 

 cur on a more or less fleshy spadix, often 

 much branched, and enclosed in a large spathe. Terminal spile 

 The inflorescence may be axial (lateral), or 



p IG> 379. 



terminal. When terminal the plant usually (After Britton 



,. rj . . . , and Brown.) 



dies after the fruit has matured. 



1 A spike is ' a form of simple inflorescence with the flowers sessile or 

 nearly so upon a more or less elongated common axis." A panicle is "a 

 loose, irregularly compound inflorescence with pedicellate flowers." A 

 raceme is "a simple inflorescence of pediceled flowers upon a common, more 

 or less elongated axis." 



