By trees then is meant, a lignous woody-plant, whose property is for the most part, to grow up and erect itself with a single stem or trunk, of a thick and more compacted substance and bulk, branching forth large and spreading boughs; the whole body and external part, cover’d and invested with a thick rind or _cortex_, more hard and durable than that of other parts; which, with expanding roots, penetrate and fixes them in the earth for stability, (and according to their nature) receive and convey nourishment to the whole: And these _terræ-filii_, are what we call timber-trees, the chief subject of our following Discourse.
Trees are likewise distinguish’d into other subordinate species; _fruticis_, frutages and shrubs; which are also lignous trees, tho’ of a lower and humbler growth, less spreading, and rising up in several stems, emerging from the same root, yielding plenty of suckers; which being separated from it, and often carrying with them some small fiber, are easily propagated and planted out for a numerous store: And this, (being clad with a more tender bark or fiber) seems to differ _frutex_ from other arborious kinds; since as to the shaft and stems of such as we account dwarf and pumilo with us, they rise often to tall and stately trees, in the more genial and benign climes.
_Suffrutrices_ are shrubs lower than the former, lignescent and more approaching to the stalky herbs, lavender, rue, &c. but not apt to decay so soon, after they have seeded; whilst both these kinds seem also little more to differ from one another, than do trees from them; all of them consisting of the same variety of parts, according to their kinds and structure, cover’d with some woody, hard membraneous, or tender rind, suitable to their constitution, and to protect them from outward injuries; producing likewise buds, leaves, blossoms and flowers, pregnant with fruit, and yielding saps, liquors and juices, _lachrymæ_, gums, and other exsudations, tho’ diversifying in shape and substance, tast, odour, and other qualities and operations, according to the nature of the species; the various structure and contexture of their several vessels and organs, whose office it is to supply the whole plant with all that is necessary to its being and perfection, after a stupendious, tho’ natural process; which minutely to describe, and analogically compare, as they perform their functions, (not altogether so different from creatures of animal life) would require an anatomical lecture; which is so learnedly and accurately done to our hands, by Dr. Grew, _Malphigius_ and other ingenious naturalists.