''Sabatia angularis'', commonly called rosepink, rose pink, square-stem rose pink or rose gentain is a

biennial Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years. In particular, it can refer to: * Biennial plant, a plant which blooms in its second year and th ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the

Gentianaceae Gentianaceae is a family of flowering plants of 103 genera and about 1600 species. Etymology The family takes its name from the genus '' Gentiana'', named after the Illyrian king Gentius. Distribution Distribution is cosmopolitan. Characteri ...

(gentain) family. It is native to central and eastern North America.

Description

''S. angularis'' grows tall, although in the first year this biennial plant appears only as a low rosette of leaves. In the second year, one or more stems rise from the basal leaves. The stems are 4-sided, appearing as a square in cross section, and

glabrous Glabrousness (from the Latin '' glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

, with flexible, thin wings on the edges. The lower part of the main stem is unbranched, with branches growing primarily from leaf nodes on the upper part. The leaves are opposite, simple, entire (without teeth), glabrous, ovate to ovate-lanceolate, and measure up to about long and wide. The plant blooms from June to September with fragrant pink (occasionally white) flowers that are up to across. The flowers have 5 petal-like

obovate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...

lobes. Yellowish triangular markings on the inner edge of the lobes give the appearance of a star in the middle of the flower. After the flowers fade, the plant produces seed capsules that contain numerous tiny seeds. Seeds are spread by the wind, and the plant will reseed itself.

Etymology

The genus name honors Liberato Sabbati, an 18th century Italian botanist. The specific epithet is Latin for "angular", referring to the square stems.

Distribution and habitat

It is geographically widespread in the United States, in the southern U.S. from Arizona in the west all the way to the east coast, and in the northern U.S. from Illinois in the west to Massachusetts in the east. It is native to Ontario but it is believed to be

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

. ''S. angularis'' is found in a variety of habitats, in glades, along roadsides, in fields, and along the margins of woods.

References

{{Taxonbar, from=Q7395934 angularis Flora of the United States Plants described in 1753 Taxa named by Carl Linnaeus