. A dictionary of the flowering plants and ferns. Botany. POLYGONACEAE 529 Polygonaceae (EP., BH.). Dicots. (Archichl. Polygonales; Curvem- bryae BH.). 30 gen., 750 sp., chiefly N. temp.; a few trop., arctic, and southern. Most are herbs whose 1. (exc. Eriogoneae) possess a peculiar sheathing stipule or ochrea (ocrea) clasping the stem above t .e leaf-base. This forms a char, feature of the fam. The infl. is primarily racemose, but the partial infls. usu. cymose. [See Eriogonum.] Fls. $, reg., cyclic or acyclic. The former have usu. the formula P 3 + 3, homochlamydeous; A 3 + 3, G (3); but man
. A dictionary of the flowering plants and ferns. Botany. POLYGONACEAE 529 Polygonaceae (EP., BH.). Dicots. (Archichl. Polygonales; Curvem- bryae BH.). 30 gen., 750 sp., chiefly N. temp.; a few trop., arctic, and southern. Most are herbs whose 1. (exc. Eriogoneae) possess a peculiar sheathing stipule or ochrea (ocrea) clasping the stem above t .e leaf-base. This forms a char, feature of the fam. The infl. is primarily racemose, but the partial infls. usu. cymose. [See Eriogonum.] Fls. $, reg., cyclic or acyclic. The former have usu. the formula P 3 + 3, homochlamydeous; A 3 + 3, G (3); but many vary from this type. Oxyria is 2-merous ; others, Eriogonum, Rheum, have branch- ing of the outer sta. The acyclic fls. have P 5, arranged according to the 2/5 phyllotaxy ( Polygonum), A 5—8, G (3). Ovary i-loc. with i erect orthotr. ov. and 3 styles. Fls. pollinated by wind or by insects. Fr. almost always a triangular nut, with smooth exterior. The seed contains an excentric curved or straight embryo surrounded by mealy endosp., sometimes ruminate. The fruits are usually wind-distributed; the persistent P usu. forms a membranous wing. Others are provided with hooks. Classification and chief genera (after Dammer) : A Flower cyclic, endosp. not ruminate. I. RUMICOIDEAE. 1. Eriogoneae (no ochrea): Chorizanthe, Eriogonum. 2. Rumiceae (ochreate): Rumex, Rheum, Floral diagram ofPolygala mvr- tifolia (after Eichler); the gland d as in P. Chiimaebuxus. Petals and bracts black; the missing petals represented by^dotted lines, the missing sta. by *.. 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 Willis, J. C. (John Christopher), 1868-1958. Cambridge [Eng. ] The University Press
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
