geophytic

Geophytic, or geophyte, describes plants that survive unfavorable seasons by means of underground storage organs. Geophytic is the adjective; geophyte the noun. These perennials withdraw to underground structures during dormancy and re-emerge when conditions improve.

Storage organs include bulbs, corms, rhizomes, and tubers. Bulbs are underground stems with fleshy storage leaves; examples include onions and many lilies. Corms are swollen stems with a protective tunic. Rhizomes are horizontal underground stems that send up new shoots; iris and many grasses are geophytic. Tubers are swollen storage organs formed from stolons or roots, as in potato. Plants may depend on these reserves for flowering and growth after dormancy and often flush rapidly when conditions favor growth.

Ecology: Geophytes are common in climates with seasonal stress—Mediterranean, temperate, and alpine regions. The underground organs protect meristems from drought, frost, or fire and coordinate growth with favorable periods. Most propagate by seed but persist mainly via the storage organ, sometimes producing clonal offsets.

Horticulture: Geophytes are valued for seasonal color in gardens and landscapes. Planting depth and drainage vary by organ: bulbs and corms are planted relatively shallow; rhizomes are placed deeper to anchor; tubers require well-drained soil that supports a dry rest period. Propagation is commonly by offsets, division, or tuber propagation.