. Elementary botany . Botany. 172 MONOCOTYLEDONS Type I. : YELLOW FLAG {Irispseudacorus).* Vegetative characters.—A perennial herb with a creeping sympodial rhizome. The leaves are mostly radical, sword-like, and overlap in an equitant manner. Inflorescence.—The main type of branching is cymose. Flower (figs. 216, 217) actino- morphic, ?, p. 1^ \ \ cyclic, epigyn- ous. Perianth 3 + 3, united to form a long tube, pe'taloid, •'^"";^^^{'f~^\f, Wli/^\J XM yellow. The r--^ :^iS"''*'ISjss,\M ll f^^^Smi^^milf free parts of the three peri- anth - leaves, which represent the outer whorl
. Elementary botany . Botany. 172 MONOCOTYLEDONS Type I. : YELLOW FLAG {Irispseudacorus).* Vegetative characters.—A perennial herb with a creeping sympodial rhizome. The leaves are mostly radical, sword-like, and overlap in an equitant manner. Inflorescence.—The main type of branching is cymose. Flower (figs. 216, 217) actino- morphic, ?, p. 1^ \ \ cyclic, epigyn- ous. Perianth 3 + 3, united to form a long tube, pe'taloid, •'^"";^^^{'f~^\f, Wli/^\J XM yellow. The r--^ :^iS"''*'ISjss,\M ll f^^^Smi^^milf free parts of the three peri- anth - leaves, which represent the outer whorl (P), are bent downwards, and each has a narrow band of Fig. 2i6.—Flower of Yellow Flag. h^irs along itS middle line. The free portions of the inner perianth-leaves (/) are smaller and incline upwards. Stamens (a) 3 -f- o, inserted on the perianth opposite to the outer whorl of perianth-leaves; anthers extrorse. Carpels three, syncarpous, inferior; the ovary (pv) three-chambered, with many ovules on an axile placenta. The style {sy) is single below, but above it divides into three broad flattened petaloid branches, which are opposite to, and arch over, the three stamens (see also fig. 218). On the surface of each band-like branch of the style there is a small thin shelf isg), whose upper face is the stigma. The three chambers of the ovary and the three branches of the style are opposite to the three stamens. This fact convinces us that the three carpels do not alternate with the three stamens. Why are the carpels thus opposite to, or superposed on, the stamens ? If we look at a floral-diagram of a Liliaceous plant, and compare it with that of the Yellow Flag, we note that the * The flowers of other species of Iris grown in gardens are sufficiently like the one here described, to be examined in place of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of thes
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1898
