Herbs annual [perennial], chlorophyllous, glabrous. Leaves basal and cauline, opposite [whorled], sessile, basal and proximal cauline sometimes ± petiolate. Inflorescences cymes (often umbelloid) or thyrses. Flowers 4-merous; calyx lobed nearly to base; corolla yellow or pale green to violet [white], campanulate or ± ovoid and scarcely opening, glabrous, lobes longer than tube, margins entire or nearly so, with 4 spurs, 1 diverging from tube below each lobe [merely protuberance], plicae between lobes absent; stamens inserted in corolla sinuses; anthers distinct; ovary sessile; style persistent, erect, short or indistinct; stigmas 2; nectaries at ends of spurs, 1 in each spur. Capsules compressed-ovoid. x = 11.

Distribution

North America, Mexico, Central America, South America, Asia, temperate to alpine areas.

Discussion

Species ca. 40 (2 in the flora).

Halenia brevicornis (Kunth) G. Don, a widespread neotropical species, occurs in northwestern Chihuahua, Mexico, and should be sought in pine woods and along arroyos in southeastern Arizona and southwestern New Mexico.

Selected References

None.

Lower Taxa

Halenia deflexa, Halenia rothrockii

Key

1	Corollas pale green to violet; spurs proximally divergent at ca. 45°, 3–5 mm (occasionally absent on small plants).	Halenia deflexa
1	Corollas yellow; spurs proxi­mally nearly hori­zontal, (3–)5–8(–16) mm.	Halenia rothrockii