subshrub; undershrub
Botanical term for a low-growing woody plant that is smaller than a typical shrub, often with only the base becoming woody.
See also: 小低木
This subshrub dies back above ground in winter, but the base becomes woody.
Compound of 亜 (a, 'sub-') + 低木 (ていぼく, 'shrub'). The exact derivation is uncertain, but it follows the pattern of scientific terminology using 亜 to indicate a subordinate or lesser category.