corm

IPA/kɔːm/
KK[kˈɔrm]IPA/kɔːrm/

corm — noun

  • cormsingular
  • cormsplural

1. the swollen underground stem of plants such as saffron crocuses and gladioli, wh

1.nounB2
Definition

the swollen underground stem of plants such as saffron crocuses and gladioli, which stores food and sends up new leaves and flowers each growing season

Example

Wei dug up the gladiolus corms in autumn to store them for winter.

phrasal collocation: dig up [plant] corms

Unlike tulip bulbs, a corm has a solid, fleshy interior with no visible layers.

comparison: corm vs bulb — solid vs layered

Common collocations
  • plant corms
  • dig up corms
  • store corms
  • crocus corm
  • gladiolus corm
  • taro corm
Synonyms
  • bulb

    commonly confused but botanically distinct — bulb has layers; corm is solid

  • tuber

    a different storage organ — tubers (e.g. potatoes) are enlarged stem tips, not stem bases

Usage Note

Distinguish from bulb: a bulb (like an onion or tulip) has layers of fleshy leaves, whereas a corm is a solid, non-layered stem. Crocuses, gladioli, and taros grow from corms, not bulbs.

Common Mistakes

I planted gladiolus bulbs in the garden.
I planted gladiolus corms in the garden.
Gladioli grow from corms (solid, non-layered stems), not from bulbs (layered leaf bases).

Synonym discussion

Sense: noun/1

Corm, bulb, tuber, and rhizome are all underground plant storage organs, but they differ in structure and origin. A corm is a solid, swollen stem base — when you cut it open, it is uniform throughout. A bulb (e.g. onion, tulip) consists of fleshy leaf layers wrapped around a central bud; peeling it reveals distinct layers. A tuber (e.g. potato) is an enlarged stem tip covered in dormant buds ("eyes") and stores starch. A rhizome (e.g. ginger, bamboo) is a horizontal stem that grows underground, sending roots downward and shoots upward. For example: "You can tell a corm from a bulb by cutting it open — a corm is solid all the way through."

bulb ↗tuber ↗rhizome

Common collocations

Nouns

Phrases

  • plant corms
  • dig up corms
  • store corms over winter

Etymology

GreekLatinEnglish

The word 'corm' comes from the Greek 'kormos', meaning the trunk or stump of a tree (the part that remains after the tree is cut). It entered scientific Latin as 'cormus' and was adopted into English botany in the mid-1800s to describe a short, swollen stem base that looks like a cut-off stump.