The floral characteristics of S. diluvialis vary, but it can be identified by a combination of features. Idealy the plant has descending flowers with a long, slender, laterally exposed lip. Sepals are basally connate for a short distance and are variably positioned, even on the same flower, being appressed to the rest of the flower, free sppreading, or ascending. A hood is only rarely evident.
Lips are ovate to lanceolate or oblong in general outline, but with a marked median constriction.
They are membranaceous in moistened material, but commonly show a limited thickening in the center. Venation is predominantly parallel, but with a variable elaboration of branched, divaricating veins in the basal half. Due to the sexual nature of S. diluvialis' reproduction, it is necessary that the welfare of the bees that pollinate it be taken into consideration. The insectiside-free buffer zone currently mandated by the U.S. Fish and Wildlife Service must be maintained around S. diluvialis populations for the entire growing season. Nesting requirements of these bees must also be considered as well as floral diversity in S. diluvialis populations in order to allow bees other opportunities to collect nectar.