Glossary of plant morphology others may form a tight spiral, or whorl, around the flower stem. First, at the base, are those non-reproductive structures involved in protecting the flower when it is still a bud, the sepals, then are those parts that play a role in attracting pollinators and are typically coloured, the petals, which together with the sepals make up the perianth (perigon, perigonium). If the perianth is differentiated, the outer whorl of sepals forms the calyx, and the inner whorl of petals, the corolla. If the perianth is not differentiated into sepals and petals, they are collectively known as tepals. In some
Scutellaria nana each borne in a calyx of sepals with a prominent ridge on the upper surface. The corolla is up to 2 centimeters long, tubular in shape, and generally white or yellowish with purple mottling on the lips. Like several other skullcap species, this plant is used medicinally. Scutellaria nana Scutellaria nana is a species of flowering plant in the mint family known by the common names dwarf skullcap and dwarf scullcap. It is native to the western United States, especially in and around the Great Basin. It grows in plateau scrub, often on volcanic soils. It is a small perennial