''Nemacladus sigmoideus'' is a species of flowering plant in the

bellflower family The family (biology), family Campanulaceae (also bellflower family), of the order (biology), order Asterales, contains nearly 2400 species in 84 genus, genera of herbaceous plant, herbaceous flowering plant, plants, shrubs, and rarely small trees ...

known by the common name sigmoid threadplant. It is native to the mountains and deserts around the intersection of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, and

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

. It is a small annual herb producing a thin, spreading purplish or brown stem no more than 12 centimeters long. Hairy, sometimes toothed oval leaves up to a centimeter long occur at the base of the plant. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is a series of zigzagging branches bearing flowers on thin

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branch ...

which are

sigmoid Sigmoid means resembling the lower-case Greek letter sigma (uppercase Σ, lowercase σ, lowercase in word-final position ς) or the Latin letter S. Specific uses include: * Sigmoid function, a mathematical function * Sigmoid colon, part of the l ...

in shape. There is a single tiny

bract In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

at the base of each pedicel. The hairy flower is under 4 millimeters long. It has five yellow-tipped white lobes.

External links

Jepson Manual TreatmentUSDA Plants ProfilePhoto gallery
Campanulaceae Flora of California Flora of Baja California Flora of Nevada Flora of Arizona Flora without expected TNC conservation status {{Campanulaceae-stub