''Bartonia virginica'' is species of flowering plant in

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 ...

. It is the commonly called yellow screwstem or yellow bartonia and it is an annual species with small pale green to yellow flowers.

Description

''Bartonia virginica'' is an annual plant, that typically has simple stems that are wiry and erect. The stems are 1–4 dm tall, with opposite, strongly ascending branches. The leaves are scale-like usually opposite. The flowers are arranging in racemose or paniculate

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

, which have commonly opposite, very upright branches and pedicels. Each flower is 3–4 mm long with lance-subulate shaped sepals. The petals are oblong in shape and usually have denticulate margins and are abruptly narrowed to a rounded or obtuse, often mucronate tip. The anthers are minutely apiculate. It flowers late summer. The diploid (2n) chromosome count is fifty-two.

Habitat

''Bartonia virginica'' grows in sphagnum bogs and wet meadows, where it is found in acids bogs with

sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

Polytrichum ''Polytrichum'' is a genus of mosses — commonly called haircap moss or hair moss — which contains approximately 70 species that cover a cosmopolitan distribution. The genus ''Polytrichum'' has a number of closely related sporophytic character ...

mosses.

Distribution

The native distribution of ''Bartonia virginica'' is eastern North America and is centered around the

Atlantic coastal plain The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth#Surface, Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Afr ...

, with scattered inland populations. It has been found in Quebec and Nova Scotia of

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

to the US states of Wisconsin south to Florida and Louisiana. It reaches the most western part of its range in eastern

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

, where it is very rare and listed as endangered, having been recorded in Goodhue and Anoka counties in white cedar swamps and peat bogs.

References

Gentianaceae Plants described in 1888 {{gentianales-stub