. Fondements de la botanique. La botanique, la botanique. 188 Fondements de la BOTANIQUE 1 de printemps sur le même point.. Cela produit une fleur-cluster appelé le umhel (Fig. 130). 199. Fleurs sessiles et Flower-Clusters. - Souvent, les pédicelles sont désireux, ou les fleurs sont sessiles, puis une modification de la grappe est produit qui s'appelle un pic, comme celle de la banane plantain (Fig. 132). Le saule, aulne, bouleau, peuplier, et beaucoup d'autres communes les arbres portent une courte, souple, plutôt scaly spike (Fig. 131), qui s'appelle un châton. Le pédoncule d'une pointe est souvent tellement courte que celle-ci pour apporter les fleurs

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. Foundations of botany. Botany; Botany. 188 FOUNDATIONS OF BOTANY 1 spring from about the same point.. This produces a flower-cluster called the umhel (Fig. 130). 199. Sessile Flowers and Flower-Clusters. — Often the pedicels are wanting, or the flowers are sessile, and then a modification of the raceme is produced which is called a spike, like that of the plantain (Fig. 132). The willow, alder, birch, poplar, and many other common trees bear a short, flexible, rather scaly spike (Fig. 131), which is called a catkin. The peduncle of a spike is often so much short- ened as to bring the flowers into a somewhat globu- lar mass. This is called a head (Fig. 132). Around the base of the head usually occurs a circle of bracts known as the involucre. The same name is given to a set of bracts which often surround the bases of the pedicels in an umbel. 200. The Composite Head. — The plants of one large group, of which the dandelion, the daisy, the thistle, and the sun- flower are well-known members, bear their flowers in close involucrate heads on a common receptacle. The whole cluster looks so much like a single flower that it is usually taken for one by non-botanical people. In many of the largest and most showy heads, like that of the sunflower and the daisy, there are two kinds of flowers, the ray-flowers, around the margin, and the tubular disk- flowers of the interior of the head (Fig. 133). The early botanists supposed the whole flower-cluster to be a single. Fig. 132. — Spike of Plantain and Head of Bed Clover.. 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 work.. Bergen, Joseph Y. (Joseph Young), 1851-1917; Eastwood, Alice, 1859-1953. Boston, Ginn & Co.

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