THE POLYPETALOUS ORDERS. 385 



717. Ord, FumariaceSB (the Fumitory Family). Smooth herbs, 

 with brittle stems, and a watery juice, alternate dissected leaves, 

 and no stipules. Flowers irregular. Calyx of two sepals. Co- 

 rolla of four petals, in pairs ; the two outer, or one of them, spurred 

 or sac-like at the base ; the two inner callous and cohering at 

 the apex, including the anthers and stigma. Stamens six, in two 

 parcels opposite the outer petals ; the filaments of each set usually 

 more or less united ; the middle one bearing a two-celled anther ; 

 the lateral with one-celled or half-anthers. Fruit a one-celled and 

 tvvo-valved pod, or round and indehiscent. Seeds with fleshy al- 

 bumen and a small embryo. Ex. Fumaria, Dicentra, Corydalis. 

 A small and unimportant tribe of plants, chiefly remarkable for 

 their singular irregular flowers ; by which alone they are distin- 

 guished, and that not very definitely, from the preceding fam- 

 ily. Its floral structure has already been explained (455, Fig. 

 294-299). 



718. Ord, Cmcifene (the Mustard Family). Herbs, with a pun- 

 gent or acrid watery juice, and alternate leaves without stipules ; 

 the flowers in racemes or corymbs, with no bracts to the pedicels. 

 Calyx of four sepals, deciduous. Corolla of four regular petals, 

 with claws, their spreading limbs forming a cross. Stamens six, 

 two of them shorter (tetradynamous, 519). Fruit a pod (called a 

 silique when much longer than broad, or a silicle when short, 615), 

 which is two-celled by a membranous partition that unites the two 

 marginal placentas, from which the two valves usually fall away. 

 Seeds with no albumen : embryo with the cotyledons folded on the 

 radicle. Ex. The Water-Cress, Radish, Mustard, Cabbage, &c. 

 A very natural order, found in every part of the world, perfectly 

 distinguished by having six tetradynamous stamens along with four 

 petals and four sepals, and by the peculiar pod. The peculiarity 

 of the stamens is explained, and the symmetry of the flower shown, 

 on p. 250. These plants have a peculiar volatile acridity (and 

 often an ethereal oil, which abounds in sulphur) dispersed through 

 every part, from which they derive their peculiar odor and sharp 

 taste, and their stimulant, rubefacient, and antiscorbutic properties. 

 The roots of some perennial species, such as the Horseradish, or 

 the seeds of annual species, as the Mustard, are used as condi- 

 ments. In some cultivated plants, the acrid principle is dispersed 

 among abundance of saccharine and mucilaginous matter, afford- 

 ing wholesome food ; as the root of the Turnip and Radish ; the 



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