are climbers. The roots are either fibrous or form tubers. Leaves form sheaths at their bases that surround the stem, much like the leaves of grasses, except that the sheaths are closed and do not have a ligule. The leaves alternate up the stem and may be two-ranked or spirally arranged. The leaf blades are simple and entire (that is, they lack any teeth or lobes), they sometimes narrow at the base, and they are often succulent. The way in which the leaves typically unfurl from bud is a distinctive feature of the family: it is termed involute, and means that the margins at the leaf base are rolled in when they first emerge. However, some groups are supervolute or convolute. The inflorescences occur either as a terminal shoot at the top of the plant, or as terminal and axillary shoots arising from lower nodes, or rarely as only axillary shoots that pierce through the leaf sheath such as in Coleotrype and Amischotolype. The inflorescence is classed as a thyrse, and each subunit is made up of cincinni; this basically means that flowers are grouped in scorpion's tail-like clusters along a central axis, although this basic ground plan can become highly modified or reduced. Inflorescences or their subunit are sometimes enclosed in a leaf-like bract often called a spathe. Flowers can have either one or many planes of symmetry; that is either zygomorphic or actinomorphic. They remain open for only a few hours after opening, after which they deliquesce. The flowers are usually all bisexual (hermaphrodite), but some species have both male and bisexual flowers (andromonoecious), the single species Callisia repens has bisexual and female flowers (gynomonoecious), and some have bisexual, male, and female flowers (polygamomonoecious). nectaries are not found in any species within the family. There are always three sepals, although they may be equal or unequal, unfused or basally fused, petal-like or green. Likewise there are always three petals, but these may be equal or in two forms, free or basally fused, white or coloured. The petals are sometimes clawed, meaning they narrow to stalk at the base where they attach to the rest of the flower. There are almost always six stamens in two whorls, but these occur in a myriad of arrangements and forms. They may be all fertile and equal or unequal, but in many genera two to four are staminodes (i.e. infertile, non-pollen producing