In the American button-bush the heads are globular, in some species of teazel elliptical, while in scabious and in composite plants, as sunflower, dandelion, thistle, centaury and marigold, they are somewhat hemispherical, with a flattened, slightly hollowed, or convex disk.
- Head (capitulum)of Marigold (Calendula), showing a congeries of flowers, enclosed by rows of bracts, i, at the base, which are collectively called an involucre.
The peat is different in character from that of northern Europe: cellular plants enter but little into its composition, and it is formed almost entirely of the roots and stems of Empetrum rubrum, a variety of the common crowberry of the Scottish hills with red berries, called by the Falklanders the " diddle-dee " berry; of Myrtus nummularia, a little creeping myrtle whose leaves are used by the shepherds as a substitute for tea; of Caltha appendiculata, a dwarf species of marsh-marigold; and of some sedges and sedge-like plants, such as Astelia pumila, Gaimardia australis and Bostkovia grandif ora.
2, i), as in marigold, dandelion, daisy, artichoke.
