This extremely natural and well-defined order is the largest (and no doubt one of the youngest?); it embraces 10–12,000 known species (in 770 genera), or about one-tenth of all Flowering-plants. They are distributed over the whole globe, but are most numerous in temperate countries; the majority prefer open spaces; a smaller number are forest-forms. They abound especially in open districts in America.

Among the substances frequently found may be mentioned: Inulin (especially in the subterranean parts), Bitter materials, Tannin, volatile oils, fatty oils in the fruits. Medicinal:[40] “Herba” of Artemisia absinthium (Wormwood) and maritima[+] (Sea-wormwood), Achillea millefolium; the leaves of Cnicus benedictus and Tussilago farfara; the unopened capitula of Artemisia maritima, var. stechmanniana; the capitula of Tanacetum, Matricaria chamomilla[+] (wild Chamomile), Anthemis nobilis[+] (common Chamomile); the separate flowers of Arnica; the roots of Arnica montana[+], Taraxacum officinale[+], Anacyclus officinarum[+], Lappa major, minor, nemorosa and tomentosa, Inula helenium and Artemisia vulgaris; the latex of Lactuca virosa[+]. The following are cultivated for food:—Lactuca sativa (Lettuce), Cichorium endivia (from E. Asia, for salads), Cynara scolymus (Artichoke, Mediterranean), Scorzonera hispanica (S. Eur.), Helianthus tuberosus (Jerusalem Artichoke, from N. Am., introduced into Europe 1616), Cichorium intybus (roots as “chicory,”) Tragopogon porrifolium (Salsafy), Artemisia dracunculus. Oil is extracted from the following (the seeds): Helianthus annuus (Peru), Madia sativa (Chili), Guizotia oleifera (Abyssinia). Dyes from: Carthamus tinctorius (Safflower, used in the preparation of rouge; Egypt), Serratula tinctoria. Insect-powder from: Pyrethrum cinerariifolium (Dalmatia) and roseum (Persia, Caucasus). The following are cultivated in houses and gardens for the sake of their scented leaves:—Tanacetum balsamita (Balsam), Artemisia abrotanum (Southernwood) and A. argentea. A great many of the genera enumerated are cultivated in dwelling-houses for the sake of the flowers; e.g. Pericallis cruenta (generally termed “Cineraria”). Asteriscus pygmæus is supposed to be the genuine “Rose of Jericho”; the involucral leaves envelop the fruits after their ripening and keep them enclosed for 8–10 months until rain occurs.

APPENDIX ON THE CLASSIFICATION OF PLANTS.

By M. C. POTTER.

The earliest systems of classification were derived from the properties and uses of plants; and it was not until some two centuries ago that any scientific grouping of plants was attempted. Aristotle and Theophrastus had adopted the groups of Trees, Shrubs and Herbs as the chief divisions of the Vegetable Kingdom, a system which persisted and was employed by Tournefort and Ray as late as the end of the 17th century. The arrangement by which these three divisions were separated into smaller divisions was often founded upon a single character, such as the formation of the corolla, the form of fruit, that of the calyx and corolla, etc. All these systems of classification which brought into close proximity plants distinguished by some one character alone, could only be considered as artificial, since plants related to one another would not necessarily be included in the same group. As the knowledge of the morphology, physiology, and reproduction of plants increased, such systems were recognised as unscientific, and it became the aim of botanists to establish a natural system, founded upon mutual relationships, which would associate together only those plants which are truly allied.

The following are some of the chief systems of classification which will show the gradual development of the natural system, and may be of service to students making use of this text-book.[41]

System of John Ray (1703).

Ray was the first botanist who recognised the importance of the one or two seed-leaves of the embryo, and initiated the division of the Flowering-plants into Monocotyledons and Dicotyledons.

System of Linnæus (1733).