Federal and State Listed Species of Texas:
Johnston’s frankenia is known only from Starr, Webb, and Zapata counties, Texas and in the adjacent states of Nuevo Leon and Tamaulipas, Mexico.
Johnston’s frankenia is a ≤30 cm tall shrub with arching stems that grows into 15-60 cm wide clumps. A fine layer of scattered hairs covers the 0.4-5 mm wide stems. Most of the year the plant is grayish to bluish green, but in the fall and winter the plant turns red. Leaves occur directly opposite each other on the stem and have 0.7-2.2 mm long stalks, which hold the leaves at a 30°-45° angle from the stem. On opposite sides of the leaf stalks are two slight wings, or flat membranous outgrowths, which wrap around the main stem. Edges of the leaf are folded under. The narrowly oval leaves are 4-13 mm long and have a mealy, whitish powder on the lower surface as well as fine hairs. Flowers are cupped by cylindrical, narrow, leaf-like structures with ridges and five, upright triangular lobes. The five (rarely six) overlapping, spoon-shaped petals are usually white and 6-10 mm long by 2.1-2.5 mm wide. The brown, egg-shaped fruit is small (2.8-3.5 mm long by 1.2-1.4 mm wide) and holds one seed.
With its slender leaves occurring opposite one another, white flowers, petite stature, and red winter appearance, Johnston’s frankenia is the only shrub of its kind in South Texas.
Johnston’s frankenia occurs in saline, chalky, clayey to sandy hillsides or flats of the South Texas thorn scrublands.
Life Cycle Events
Flowering occurs throughout the year after sufficient rain.
Johnston’s frankenia can be found and identified year-round.
- Rare Plants of Texas
- U.S. Fish and Wildlife Service
- Correll, D.S. and M.C. Johnston. 1970. Manual of the vascular plants of Texas. Texas Research Foundation. Renner, TX.
- Carr, W.R. 1995. Rare plant surveys on Lower Rio Grande Valley National Wildlife Refuge tracts, December 1993-July 1995. Austin: Texas Parks & Wildlife Department.
- Janssen, G.K. 1999. Site characteristics and management of Johnston’s frankenia (Frankenia johnstonii). Section 6 final report. Austin: Texas Parks & Wildlife Department.
- Janssen, G.K. 2003. The conservation of Johnston's frankenia (Frankenia johnstonii): annual monitoring, a requirement of delisting. Section 6 final report. Austin: Texas Parks & Wildlife Department.
- Poole, J.M. and G.K. Janssen. 1997. Managing and monitoring rare and endangered plants on highway right-of-ways in Texas. Section 6 final report. Austin: Texas Parks & Wildlife Department.