. Class-book of botany [microform] : being outlines of the structures, physiology, and classification of plants : with a flora of the United States and Canada. Botany; Botany; Plants; Plants; Botanique; Botanique; Plantes; Botanique. THE OVULES. ioy. 415 416 417 414 412 411 410 406, Pistil of Cclosia, tlie pericarp (k'tiiclied shDwing the young ovules. 413, Flower of Rhu- barb ; pericarp rciuoved siiowini: the young ovule. 407, A biniilar ovule (orthotropous) of Polyironum. 40s. Tiie same, full fjrown ; foramen at top. 409, Section showing its two coats, nucleus un<l sac. 410, Anatropous ov
. Class-book of botany [microform] : being outlines of the structures, physiology, and classification of plants : with a flora of the United States and Canada. Botany; Botany; Plants; Plants; Botanique; Botanique; Plantes; Botanique. THE OVULES. ioy. 415 416 417 414 412 411 410 406, Pistil of Cclosia, tlie pericarp (k'tiiclied shDwing the young ovules. 413, Flower of Rhu- barb ; pericarp rciuoved siiowini: the young ovule. 407, A biniilar ovule (orthotropous) of Polyironum. 40s. Tiie same, full fjrown ; foramen at top. 409, Section showing its two coats, nucleus un<l sac. 410, Anatropous ovule, as of columbine; <i, foramen. 411, Section of tiame. 412, ("aiupylotropous ovule, as of Bean; a, foramen. 414, Section of a cherry, ovule anatropous, susitended. Section of carpel of Ranunculus; ovule ascending. 416, Seuecio; •vule erect. 417, Ilippuris; ovule pendulous. 633. The number of ovules in the ovary varies from one to hun- dreds. Thus in buttercups, Coinpositae and grasses the ovule is solitary; in Unibeliferae it is also solitary in each of the two carpels; in the Pea Order they are definite, being but few ; in Mullein, Poppy, indefinite^ oo), too many to be readily counted. 534. The position of the ovule in the cell is defined by certain terms as follows; erect, when it grows upwards from the base of the cell, as in Compositae ; ascending, when it turns upwards from its point of lateral attachment; horizontal, when neither turning upwards nor downwards; pendulous, when turned downwards, and suspended, when growing directly downwards from the top of the cell, as in birch. (415, 416, 417, 419). 535. The ovule at the time of flowering is soft and pvdpy, consisting of a nucleus within two coats, supported on a stalk. The stalk is 'iX funiculus ; the point of its juncture with the base of the nucleus is the chalaza. The nucleus was first formed, then the legmen or inner coat grew up from the chalaza and covered it, and lastly the outer coat, the
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Keywords: ., bookcentury1800, bookdecade, booksubjectbotany, booksubjectplants
