When I'd looked at the pictures originally I'd thought they were taller than that, I guess looking at the other plants beside and now knowing that's what you meant, I can get a better idea and now I see what you mean. I was trying to fit what you were saying in with the AHS registration instructions:
Evergreen (ev.)
These daylilies retain their foliage throughout the year. In the north, these plants over
winter as a mound of frozen pale green foliage. Evergreens may resume growth during a
mid-winter thaw in mild climates.
Semi-evergreen (sev.)
The foliage of these daylilies dies back nearly to the ground in very cold climates. Some
green will be seen near the base. Generally, semi-evergreens wait until spring to resume
growth.
Dormant (dor.)
These daylilies lose their foliage completely before or shortly after frost and over winter
with pointed foliage buds, usually just beneath the soil surface. Dormants will resume
growth in spring.
