114 LEGUMINOS^ 



phous or diadelphous, 9 being united by their filaments and the 

 posterior one separate. In a few exotic species the legume 

 becomes fleshy and drupaceous ; but then the papilionaceous 

 flower remains as a means of identification, whilst in the sub-orders 

 in which the flower is not papilionaceous the fruit remains the 

 characteristic legume. Among British species the chief varieties 

 of form in the pod are those of the Bird's-foot i^OniitJiopus) and 

 others, where it is imperfectly jointed, and in Medick {Medicdgo), 

 where it is often spirally twisted, so as to resemble a snail-shell. 

 Many members of the Order display peculiar irritability in their 

 leaves. Almost all the plants of the Order which have compound 

 leaves fold them together in what is called " sleep " at night ; but 

 the species of Mimdsa, particularly M. pudica and M. sensilwa, 

 which are known as Sensitive plants, close up in a remarkable 

 manner when touched ; whilst those of the Telegraph plant 

 {^Hedysdrum gyrans) are in constant motion. The Order is repre- 

 sented in all parts of the world and competes with the GraminecE 

 diXidi Pal mace CE in its great and varied utility to man. The seeds of 

 many species, under the general name of pulse, afford most 

 nutritious food, exceptionally rich in nitrogen, for man and other 

 animals — Peas, Beans, and Lentils, for example; others supply 

 valuable fodder, such as Clover, Vetches, and Lucerne ; the Rose- 

 woods are the best known of many excellent timber-trees ; Gum 

 Arabic, Gum Tragacanth, and the Wattle Gums of Australia are 

 products of the order ; Wattle-bark, Catechu, and Kino are among 

 the valuable astringent substances used in tanning ; Logwood and 

 indigo are the chief dyes in the Order. Not a few are poisonous, 

 especially in the seed, of which the Laburnum is a familiar example. 

 Others, the seeds of which are eminently nutritious, have proper- 

 ties of an opposite nature residing in other parts of the plant. The 

 roots of the Kidney Bean, for instance, are dangerously narcotic. 

 Many species are used in medicine, such as Tamarinds, Liquorice, 

 and Senna. The excessively poisonous Ordeal Bean of Calabar 

 {Physostigmd) contains an alkaloid which is of use in ophthalmic 

 surgery, as it contracts the pupil of the eye. The sweet pods of 

 the Carob-tree {Cerafonia Siliqua) are known as Locust beans, or 

 St. John's Bread, being supposed by some to have been the food 

 of St. John the Baptist in the wilderness. They are eaten by 

 children ; but are chiefly used to fatten cattle. There are about 

 eighty British species in the Order, the species of Genista, Furze, 

 Broom, and Restharrow — about 10 in all — being shrubby or woody, 

 and the rest herbaceous. For convenience of reference the British 

 genera are arranged in three groups, comprising six tribes, as 

 follows - — 



