Houseplant clinic: will my euphorbia ever sprout again?

Don’t panic! This plant has a natural seasonal rhythm, so resist the urge to overwater when it’s bare

What’s the problem?
My Euphorbia ritchiei sprouted a leaf, but it was accidentally knocked off and now it’s bare. Will it grow back?

Diagnosis
Please don’t panic, this east African succulent is unusual in that it grows fleshy leaves along its ridged stems during its growing season, then often sheds them in winter. In its native Kenya, rainfall is seasonal. The plant responds by producing foliage in the wet season, then dropping its leaves in the dry season to conserve water and energy. The green stems continue to photosynthesise so the plant can survive leafless for long periods.