Prior to this study no published data were available regarding Zapata bladderpod abundance, phenology, or spatial distribution with respect to conspecifics or other plants.
During an exhaustive search of the tract in July 1997, Zapata bladderpod were marked to determine where the largest concentrations occurred.
A systematic random sampling method was used to distribute 30 sampling plots across the Zapata bladderpod population area.
Zapata bladderpod surveys were conducted on 31 July 1997, 15 March 2001, 15 June 2001, 10 September 2002, and 22 September 2003.
The developmental condition for each flowering pedicel on each bladderpod was recorded.
The spatial distribution of plants in relation to Zapata bladderpod was recorded from the sampling plots in September 2003.
Plot radius was based on the average longest-leaf of local Zapata bladderpods (11 cm) plus the 10 cm horizontal distance as used in the Zapata bladderpod survey.
A member of the mustard family (Brassicaceae), the Zapata bladderpod is one of many plant species with ranges that straddle the Mexico/United States border.
The Zapata bladderpod has not been verified in Mexico in recent years.
The recovery plan is an important tool for private landowners who may be interested in contributing to Zapata bladderpod recovery, and it will stimulate cooperation between the United States and Mexico.