. Foundations of botany. Botany; Botany. HOW PLAin'S PROTECT THEMSELTES 349 417. Plants with Weapons for Defense.' â Multitudes of plants, which might otherwise have been subject to the attacks of grazing or browsing animals, have acquired what have with reason been called weapons. Shrubs and trees not infrequently produce sharp-pointed branches, familiar in our own crab-apple, wild plum, thorn trees, and above all in the honey, locust (Fig. 34), whose formida- ble thorns often branch in a very complicated man- ner. Thorns, which are really modified leaves, are very perfectly exempli- fied in
. Foundations of botany. Botany; Botany. HOW PLAin'S PROTECT THEMSELTES 349 417. Plants with Weapons for Defense.' â Multitudes of plants, which might otherwise have been subject to the attacks of grazing or browsing animals, have acquired what have with reason been called weapons. Shrubs and trees not infrequently produce sharp-pointed branches, familiar in our own crab-apple, wild plum, thorn trees, and above all in the honey, locust (Fig. 34), whose formida- ble thorns often branch in a very complicated man- ner. Thorns, which are really modified leaves, are very perfectly exempli- fied in the barberry (Fig. â 243). It is much com- moner to find the leaf . - ., VvT" "^\ Kg. 244. âLeaf of a NigM- extending its midrib or M\ ^ shade (.Solanum atropw- its veins out into spiny ^ ^^>- points, as the thistle does, or bearing spines or prickles on its midrib, as is the case with the nightshade shown in Fig. 244, and with so many roses. Prickles, which are merely hard, sharp-pointed projections from the epidermis, are of too common occurrence to need illustration. Stipules are not infrequently found occurring as thorns, and in our common locust (Fig. 246) the bud, or the very young shoot which proceeds from it, is admirably pro- tected by the jutting thorn on either side. 418. Pointed, Barbed, and Stinging Hairs. â Needle- pointed hairs are an efficient defensive weapon of many plants. Sometimes these hairs are roughened, like those ' 1 See Kerner and Oliver's Natural History of Plants, Vol. I, p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bergen, Joseph Y. (Joseph Young), 1851-1917; Eastwood, Alice, 1859-1953. Boston, Ginn & Co.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
