E. discolor calyces [Jeff Davis Co.].

by Bob Harms ()

Venation patterns for Texas Evolvulus taxa using the distinctions noted in van Ooststroom 1934 were studied by clearing leaves to remove the pubescence concealing the venation. [The process of clearing & staining the leaves.]

30 leaves were selected for 4 taxa representing all areas of Texas (26), Chihuahua (1) & Coahuila (1) of northern Mexico, Missouri (1) and Utah (1). The Texas specimens were from: Trans-Pecos, 14; Panhandle, 3; South Texas, 2; North & Central Texas, 9. The 4 taxa studied fell into 5 groups: E. alsinoides, 5; E. arenarius, 2; E. nuttallianus, 11; E. sericeus 4, E. discolor 9 — including 7 collections from Mexico and the Trans-Pecos currently determined as E. nuttallianus which I had determined on other grounds (primarily habit and sepal form) to be E. sericeus.

Presented below are scans of the 15 best results from the 30 leafs cleared.

E. alsinoides

E. alsinoides — Val Verde Co.	E. alsinoides — Presidio Co.

E. nuttallianus

E. nuttallianus — Utah	E. nuttallianus — Dallas Co.

E. nuttallianus — Missouri	E. nuttallianus — Bell Co.

E. nuttallianus — Culberson Co.	E. nuttallianus — Presidio Co.

E. arenarius

E. arenarius — Gaines Co.

E. sericeus: East of the Trans-Pecos

E. sericeus — Brazos Co.	E. sericeus — Hays Co.

E. sericeus — Kleberg Co.

E. discolor: Trans-Pecos & Mexico

E. discolor — Jeff Davis Co.	E. discolor (previously as E. nuttallianus) — Brewster Co.

E. discolor (previously as E. nuttallianus) — Chihuahua