The genera of South African plants : arranged according to the natural system / by William Henry Harvey.
- William H. Harvey
- Date:
- 1868
Licence: Public Domain Mark
Credit: The genera of South African plants : arranged according to the natural system / by William Henry Harvey. Source: Wellcome Collection.
18/556
![§ 1. The Plant in general, 6. Under the common term Plant botanists include every being that has vegetable life ; from the lofty forest tree to the moss upon its stem, tho mouldiness on our decajdng provisions, or the green scum that floats on stagnant water. 6. Every portion of a plant which has a distinct ofiice or function to perform in the operations of vegetable life is called an Organ. 7. The organs of plants are of two kinds, tho elementary and the compound. 8. Elementary organs are those ultimate pai-ts or tissues of which tho body of a compound vegetable consists, viz. cellular tissue, woody tissue, and vascular tissue. 9. Compound organs are formed by various combinations of tho elemen- tary, and appear under tho form of Root, Stem, Leaves, Flowers, Fruit. Of those tho three first, whose function is to assist in the growth of tho plant, are termed Organs of vegetation ; and tho two last, whoso office is tho formation of seed, are the Organs of reproduction. 10. All those compound organs, in some shape or other, exist at some period of tho life of most, if not all, flowering plants, technically called pheenogamous or phanerogamous plants ; which all bear flowers of more or loss com])lcx structiu'o, and are all propagated by seeds containing a germ or embryo plantlet. Elowerless or cryptogamic plants (Ferns, Mosses, Fungi, Lichens, Seaweeds, etc.) have either very imperfect representatives of flowers, or aro absolutely flowerless ; and are invariably propagated, not bj' seeds, but by spo7-cs, which do not contain any distinct geim or embryo. 11. Tho elementary organs 'Nvill bo described afterwards ; wo shall con- sider tho compound under tho foUo'wing heads: Root, Rootstock, Stem, Leaves, Stipules, Bracts, Inflorescence, Flower, Pcxianth, Disk, Pistil, Ovule, Receptacle, Fruit, Seed. $ 2. The Boot. 12. Tho primary Root, or descending axis, grows downwai-ds from tho base of tho stem, divides and spreads in tho earth or water, and absorbs food for tho plant through tho extremities of its branches. 13. Roots ordinarily produce neither buds nor leaves ; their branches, called/ires when slender and long, proceed irrogulai-ly from any part of their surface ; and they increase in length by constant small additions to their extremities. 14. Though roots proceed usually from tho base of tho stem or root- stock, they may bo formed at tho base of any bud, especially if the Inid lio along tho ground, or elsewhere on tho stem, if this is placed in circum- stances favourable for their development. 15. Roots aro fibrous, when they consist chiefly of slender fibres ; tuberous, when either tho main root or its branches are thickened into short, fleshy, or woody masses called tubers ; ^ tap~7'oots, when tho main root descends perpendicularly, emitting only very few fibrils, as in tho Cairot. - ^ § 3. The Bdotstoch or Bhizome. 16. The Stock of a herbaceous perennial, in its complete state, includes a small portion of the summits of the previous year’s roots, as wcU as of the base of the previous year’s stems. Such stocks will increase yearly so as at length to form dense tufts. They will often preserve through the](https://iiif.wellcomecollection.org/image/b28117347_0018.jp2/full/800%2C/0/default.jpg)
