General: Southwestern Ringstem (Anulocaulis leiosolenus var. leiosolenus), also called Sticky Ringstem, is a perennial forb that exists as a basal rosette of leaves before sending up tall, thin flowering stalks in the spring. The basal leaves are rounded, coarse-edged, and have a rough surface. The stems have rings of a sticky substance that can entrap small insects. Flowers are borne singly or in loose clusters. Flowers are trumpet shaped: 25–35 mm long and flared at the end. Tube greenish bronze, flaring parts white to pink. Stamens 3, exserted 25–40 mm beyond the flower. Perianth 25-35 mm; perianth lobes flared but not reflexed.

Southwestern Ringstem is a rare component of vegetation communities on barren mud hills with concentrations of gypsum in the Lower Sonoran (Creosote-Bursage Flats) and Upper Sonoran (Mojave Desert Scrub) life zones.

Around Las Vegas, look for Southwestern Ringstem on muddy and gypsum soils around Lake Mead NRA region and in Gold Butte National Monument.

Family: Four O'Clock (Nyctaginaceae). Other varieties of this plant can be found from Arizona to west Texas.