Nature and development of plants . 341, B-D). The styleis two lobed, the stigma usually appearing as a line on the innersurface of the lobes and the single, one-ovuled carpel maturesas an akene. Scale-like bracts, the chaff, are often associatedwith the flowers (Fig. 341, B). The nectar formed from theglands at the base of the style is concealed at the bottom of thecorolla tube. (a) The Chicory Family.—This family is distinguished by allthe flowers of the head being ligulate (Fig. 339) and mostly yel-low in color and by the possession of milky, bitter or acrid juices. 454 THE CAMPANULALES Here
Nature and development of plants . 341, B-D). The styleis two lobed, the stigma usually appearing as a line on the innersurface of the lobes and the single, one-ovuled carpel maturesas an akene. Scale-like bracts, the chaff, are often associatedwith the flowers (Fig. 341, B). The nectar formed from theglands at the base of the style is concealed at the bottom of thecorolla tube. (a) The Chicory Family.—This family is distinguished by allthe flowers of the head being ligulate (Fig. 339) and mostly yel-low in color and by the possession of milky, bitter or acrid juices. 454 THE CAMPANULALES Here belong the goats beard (Adopogon), hawkbit (Leontodon),sow thistle (Souchiis), hawkweed (Hieracium), rattlesnake root(Nabcdus), as well as several introduced and native plants thatare cultivated, as the dandelion (Taraxacum), species of chicory(Ciclioriimi), salsify (Tragopogon), lettuce (Lactuca). Thecharacter of the head, flower and fruit of this family are wellshown in the dandelion (Fig. 339). All the flowers are Fig. 339. Flowers and fruit of Taraxacum: A, sectional view of in-florescence—in, involucre. The flowers in the center of the head not asyet in bloom. B, an unopened flower. The thread-like calyx (pappus)and corolla arising from the ovary, 0. C, corolla opening. D, later stage,the style has elongated, sweeping the spores from the sheath of anthers,an, and the two stigmatic lobes are beginning to open. E, flower in fullbloom, the stigma lobes recurving. F, mature fruit. The pappus is liftedup on a long, slender outgrowth of the ovary, 0. the five lobes frequently to be seen on the margin of the corollaindicating the number of petals, and the calyx assumes the formof minute hairs (Fig. 339, B-E). The five filaments adhere tothe tube of the corolla while the anthers form a cylinder aboutthe style and discharge their spores before the flower opens. Thestyle begins to elongate as soon as the flower opens and pushes DEVELOPMENT OF PLANTS 455 out the spore
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