Polycnemum

Herbs, annual, glabrous or pubescent. Stems erect or procumbent, not jointed, not armed, not fleshy. Leaves alternate; blade awl-shaped, triangular in cross section, rigid, margins entire, apex terminating in soft or stiff, flattened spine. Inflorescences solitary flowers in axils of leaflike bracts. Flowers bisexual; perianth segments 5, membranous; stamens usually 3 (occasionally 1–2 with fertile anthers); stigmas 2-branched, filiform. Fruiting structures: bracteoles 2; utricles indehiscent or dehiscence circumscissile; pericarp white and somewhat fleshy, ± equaling seeds, membranous. Seeds vertical, flattened, seed coat black, pitted or smooth; embryo annular, perisperm copious. x = 9.

Distribution

mid Europe to s Russia and n Africa.

Discussion

Species ca. 7 (2 in the flora).

There are few records of Polycnemum in North American herbaria and populations are less widespread than reported in the early part of the 20th century. Reports of Polycnemum arvense from British Columbia have not been reconfirmed in recent years, and the present-day range of P. majus may be restricted to Canada. The report of P. verrucosum (a species with glaucous leaves and elongated perianth bracts) from Nova Scotia is based on a specimen that fits the morphological description of P. majus. Under-reporting may occur because Polycnemum is confused easily with immature specimens of Salsola.

Selected References

None.

Lower Taxa

Polycnemum arvense, Polycnemum majus

Key

1	Bracteoles to 2 times perianth length; leaves (at least some) greater than 10 mm, spine-tip stiff	Polycnemum majus
1	Bracteoles equaling perianth length; leaves less than 12 mm, spine-tip flexible	Polycnemum arvense