Gladiolus flowering
Mary Sue Ittner (Mon, 06 Aug 2012 18:04:59 PDT)

The Gladiolus book has a key for the former Homoglossums. I spoke to
Dee Snijman at one of the IBSA Symposiums thanking her for the keys
and she seemed amazed. "Do you use the keys she said?" I thought to
myself that I try, but not always with confidence. Not including
Namaqualand makes it a bit dicey, but here we go. This muddies the
waters a bit.

The upper lateral tepals are about as long to slightly longer than
the dorsal: leaf blades oblong to oval in cross section, the margins
and midribs thickened; corm tunics hard and more or less woody in
texture, decaying into vertical segments from below (G. watsonius, G.
teretifolius )

The upper lateral tepals somewhat shorter to less than half as long
as the dorsal; leaf blades x-shaped in cross section, the margins and
the edges of the midribs thickened; corm tunics cartilaginous to
fairly soft in texture, decaying with age into fine vertical fibers
(Quite a few including G. quadrangularis, G. priorii)

So the corms could be helpful too. I think the upper tepals in your
photos look about as long as the dorsal.
Between the two:
Upper and lower lateral tepals lanceolate, more than twice as long as
wide; blade of the lowermost leaf linear (oblong in cross section,
(1.5-)3-5 mm at the widest = G. watsonius

Upper and lower lateral tepals ovate, as much as twice as long as
wide; blade of the lowermost leaf oval in cross section, 1-2 mm at
the widest = G. teretifolius

I hope this helps.

Mary Sue