All species within the genus are
perennials that grow from in height. They have
rhizomes which can either be long, slender or short and thick or sometimes
cormoid, all of which often become woody. The stems can be ascending to erect and are typically simple, though they are in rare cases they branch proximally, i.e. near the point of attachment. They can be glabrous to more or less densely hairy, and are generally eglandular, meaning they lack
glands, though they can sometimes be stipitate-glandular, meaning glands are present on a
stipe. The
leaves are always alternate. Both basal and cauline leaves, i.e. leaves growing on the stem, are present, and these may be either sessile or petiolate, meaning lacking or having a
leaf stalk. The blades of the leaves may be anything from cordate, ovate, obovate, elliptic, or oblong in shape to spatulate, oblanceolate, or lanceolate. They are usually gradually reduced distally, meaning they taper towards the apex. The leaf margins can be entire or serrate, i.e. toothed, though they may also occasionally be spinulose-serrate, that is being toothed with small spines. The leaf surfaces are glabrate to hairy and are usually eglandular, though they may sometimes be stipitate-glandular. ==References==