GENERAL CHARACTERISTICS OF THE LEGUMINOS^E 



183 



wings 



.standard 



Inflorescence and Flowers. The inflorescence is a raceme (golden 

 chain}, an umbel, a spike-like raceme, or a head (capitulum), as in the 

 clovers. The flowers are regular (Mimosa), or mostly irregular with three 

 to five sepals, and usually five petals with perigynous insertion. As 

 there are three types of flowers, their structure may be described by ref- 

 erence to the three subfamilies, viz., 

 Papilionoidece (Fig. 73) Casalpinoidea 

 and Mimosoidea (Fig. 74). The 

 papilionaceous flowers are irregular 

 with three to five sepals and five 

 petals, the posterior one of which is 

 called the vexillum, standard, or flag 

 petal; two lateral petals, the wings, or 

 alae, and two interior petals united by 

 their edges to form the keel, or carina 

 (Figs. 73 and 75). The stamens are 

 perigynous in insertion, ten in number, 

 monadelphous, diadelphous, or occa- 

 sionally distinct. The standard in- 

 closes the lateral petals in this sub- 

 family, so that the estivation is known 

 as the vexillary type. The caesal- 

 piniaceous flowers are irregular, or re- 

 gular, with the odd petal, or standard, 

 inclosed by the two lateral petals, or 

 wings, and the stamens are generally 

 ten in number and distinct. The 

 mimosaceous flower is regular with 

 three to five petals, which are valvate 

 in the bud and the stamens are 

 numerous, or indefinite, and distinct 

 (see floral diagrams in figures 73 and ( phaseo ^ vulgaris) A. spiral keel; B, 



entire flower, x 2 >. (Robbins.) 

 74-) 



Ovary and Fruit. The ovary is superior in all three subfamilies. It 

 is apocarpous with one carpel. It is one-celled with parietal placenta. 

 The style may be long or short, bent, or straight (Fig. 76). The fruit is a 

 pod, or legume, occasionally a transversely divided pod, known as the loment. 

 Each division of the loment is usually one-seeded. The seeds are large 



FIG. 75. Common kidney bean 



