THE PEA FAMILY 



FABACEiE Reichenbach 



HIS is a very large family, comprising some 325 genera, including 

 probably 5000 species of trees, shrubs, herbs, woody and herbaceous 

 climbers, of wide distribution, most abundant in the warmer temper- 

 ate regions of both hemispheres. They are of vast and varied economic 

 importance; the seeds of many, as beans, peas, and peanuts, are of the highest 

 nutritive value on account of the large quantity of albuminous matter stored in 

 them. Many are of great medicinal value, and some of them are very poisonous, 

 such as the Calabar bean, the seed of Physostigma venenosum Balfour, and the 

 bright scarlet seeds of Abriis precatorius Linnaeus, a tropical climbing vine, are as 

 intensely poisonous as they are brilHant. Many furnish valuable timber, and 

 numerous genera supply important forage plants such as the Clovers, Alfalfa, 

 Lupines, and MeHlots. Their value as concentrators of nitrogen in the soil is ines- 

 timable; many dyes are also derived from plants of this family, indigo being the 

 most important, and the ornamental plants belonging here are ver\' numerous. 



The FahacecB have alternate stipulate leaves which are mostly compound. 

 The flowers are usually perfect, rarely polygamous or dioecious, sohtan," or in vari- 

 ous simple or compound clusters, axillary or terminal, irregular. The calyx is 4- 

 or 5-toothed, rarely cleft, and often 2-Hpped; corolla pea-Hke (papiUonaceous) ; its 

 5 petals are distinct or somewhat united, usually of 3 kinds, the broad upper one, 

 which in the bud surrounds or encloses the others, is known as the standard or 

 banner, the 2 lateral are called the wings, and the 2 lower, more or less united, are 

 called the keel; stamens 10 or sometimes only 9, rarely there are but 5; their fila- 

 ments are usually united into i or 2 groups, rarely separate; usually 9 are united 

 into a spHt tube, the loth being free; pistil a single carpel, simple and superior; 

 the ovary i -celled or several-celled by transverse partitions; style simple; stigma 

 terminal, obhque or lateral; ovules i to many. The fruit is a 2-valved dehiscent 

 legume, or indehiscent, often more or less modified ; seeds usually without endo- 

 sperm, the cotyledons thick. 



There are about 75 genera with some 1250 species in our area; the following 

 are arborescent: 



Stamens 10; filaments distinct. 



Flowers racemose; pods swollen, constricted between the seeds. i. Sophora. 



Flowers paniculate; pods flattened. 2. Cladrastris. 



Stamens 10 or fewer; filaments united in one or two groups. 



Leaves more than 3-foliolate. 



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