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
Collinsia corymbosa is a dense whorl of several distinctive flowers. Each has a hairy calyx of lobed reddish sepals and a corolla up to about 2 centimeters long. The flower has two small upper lobes and three longer lower lobes which come together in a nearly tubular shape. It is generally white with a light purple tint. The smaller upper lobes curl back and dry to brown at their lips. Collinsia corymbosa Collinsia corymbosa is a species of flowering plant in the plantain family known by the common name round-headed Chinese houses. It is endemic to the coastline of California north of