. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 202 FLORAL ENVELOPES—COEOLLA. summit of the petals in the form of a long process, as in Strophanthus hispidus, where it extends for seven inches; and at other times it ends in a free point or cuspis, and the petal becomes cuspidate; or the pro- longed extremity is folded downwards or inflexed, as in Umbelliferse (fig. 306), so that the apex approaches the base. If the median vein divides into two, the space between, the divisions may be filled up so as to leave only a
. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 202 FLORAL ENVELOPES—COEOLLA. summit of the petals in the form of a long process, as in Strophanthus hispidus, where it extends for seven inches; and at other times it ends in a free point or cuspis, and the petal becomes cuspidate; or the pro- longed extremity is folded downwards or inflexed, as in Umbelliferse (fig. 306), so that the apex approaches the base. If the median vein divides into two, the space between, the divisions may be filled up so as to leave only a slight deficiency, and thus the petal .becomes emarginate; or the deficiency may be greater, while the limb gradually expands from below upwards, and its extremity becomes two-lobed, so that the petal is obcordate. If the separation extends to the middle, it is hifid; if to near the base, bipartite, as in Chickweed (fig. 307 I). In the same way as in leaves, the venation of the petals is sometimes unequal, and the cellular tissue is developed more on one side than on the other, thus giving rise to an ohliqae petal. The limb of the petal may be flat or concave, or hoUowed like a boat, cj/mfei/brm or navicular {cymha, a boat, navis, a ship), or like a spoon, cochleariform (cochleare, a spoon). In the case of the navicular petal, the median vein forms a marked keel. In Hellebore the petals _^^__^ become folded in a tubular ^Jiv^ form, resembling a horn; in ^ * Aconite (fig. 308) some of the petals, p, resemble a hoUow curved horn, supported on a grooved stalk; while in Colum- bine (fig. 309) Violet, Snap- dragon, and Centranthus, one or all of them are prolonged in the form of a spur, and are calcarate {calcar, a spur). In Valeriana, Antirrhinum, and Corydalis, the spur is very short, and the corolla or petal is said to be gibbous (gibbus, a bunch or swelling), or saccate at the base. In some Borar ginacese (fig. 322) there are foldings at the upper part of the tube of the corol
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
