[Taxacom] Botanical morphology term

[John Grehan]

Is there an accepted botanical term for the part of the stem just above
ground, especially for small plants? I am aware of the corm but this
appears to refer to a swollen region only. This is in relation to
caterpillars that live in the ground but may feed on the basal part of the
stem within a centimeter or so above the ground surface.

John Grehan