OBCORDATUM R.T.Clausen, 1941

Distribution : Mexico (Veracruz : Orizaba and Cofre de Perote).

Description (according to IHSP 2003) :

Glabrous, perennial subshrubs with caespitose, erect or ascending, much branched stems with peeling bark and easily breaking branches.

Leaves decussate, sometimes alternate, obcordate, obovate or suborbicular, emarginate or broadly rounded, shortly spurred, glaucous, bluish, 7 – 29 x 6 – 25 mm, flowering branches erect.

Inflorescences cymes with 1 – 5 branches, bracts elliptic or obovate, pedicels 1 – 7 mm.

Flowers 5- (rarely 4- or 6-)merous, sepals basally free, sometimes shortly spurred, unequal, oblanceolate-oblong or elliptic-oblong, obtuse, glaucous, pale green, 6.5 – 15.1 x 2.3 – 5.9 mm, petals basally slightly connate, lanceolate, acute or obtuse, mucronate, carinate, glaucous, yellow, greenish at the base, ± 10 mm, anthers yellow.

Cytology : 2n = 68

Note :

When not in flower S. obcordatum and S. palmeri can easily be confused.