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§ 6. Scales, Bracts, and Stipules.

58. Scales (Squamce) are leaves very much reduced in size, usually sessile, seldom green or capable of performing the respiratory functions of leaves. In other words, they are organs resembling leaves in their position on the plant, but differing in size, colour, texture, and functions. They are most frequent on the stock of perennial plants, or at the base of annual branches, especially on the buds of future shoots, when they serve apparently to protect the dormant living germ from the rigovir of winter. In the latter case they are usually short, broad, close together, and more or less imbricated, that is, overlapping each other Hke the tiles of a roof. It is this arrangement as well as their usual shape that has suggested the name of scales, borrowed from the scales of a fish. Imbricated scales, bracts, or leaves, are said to be squarrose, when their tips are pointed and very spreading or recurved.

59. Sometimes, however, most or aU. the leaves of the plant are reduced to small scales, in which case they do not appear to perform any particular function. The name of scales is also given to any small broad scale-Hke appendages or reduced organs, whether in the flower or any other part of the plant.

60. Bracts {Bractece) are the upper leaves of a plant in flower (either all those of the flowering branches, or only one or two immediately under the flower), when different from the stem-leaves in size, shape, 0010^0", or arrangement. They are generally much smaller and more sessile. They often partake of the colour of the flower, although they very frequently also retain the green colour of the leaves. When small they are often called scales.

61. Floral leaves or leafy bracts are generally the lower bracts on the upper leaves at the base of the flowering branches, intermediate in size, shape, or arrangement, between the stem-leaves and the upper bracts.

62. Bracteoles are the one or two last bracts under each flower, when they differ materially in size, shape, or arrangement from the other bracts.

63. Stipules are leaf-like or scale-hke appendages at the base of the leaf-stalk, or on the node of the stem. When present there are generally two, one on each side of the leaf, and they sometimes appear to protect the young leaf before it is developed. They are however exceedingly variable in size and appearance, sometimes exactly like the true leaves except that they have no buds in their axils, or looking like the leaflets of a compound leaf, sometimes apparently the only leaves of the plant ; generally small and narrow, sometimes reduced to minute scales, spots, or scars, sometimes united into one opposite the leaf, or more or less united with, or adnate to the petiole, or quite detached from the leaf, and forming a ring or sheath round the stem in the axil of the leaf. In a great number of plants they are entirely wanting.

64. Stipellce, or secondary stipules, are similar organs, sometimes found on com- pound leaves at the points where the leaflets are inserted.

65. When scales, bracts, or stipules, or almost any part of the plant besides leaves and flowers are stalked, they are said to be stipitate^ from stipes^ a stalJc,