from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The part of a plant embryo or seedling plant that is between the cotyledons and the radicle or root.

from The Century Dictionary.

  • noun In botany, that part of the axis which is below the cotyledons. Also called the caulicle, and erroneously the radicle.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun botany In plants with seeds, that portion of the embryo or seedling between the root and cotyledons.


from The American Heritage® Dictionary of the English Language, 4th Edition

[hypo– + cotyl(edon).]


Help support Wordnik (and make this page ad-free) by adopting the word hypocotyl.


  • Arabidopsis thaliana, the embryonic stem or hypocotyl grows rapidly by longitudinal cell expansion in a process referred to as hypocotyl elongation.

    PLoS Biology: New Articles

  •  It†™ s also grown for its fleshy hypocotyl which is used as medicinal herbal.

    MyLinkVault Newest Links

  • For some reason, I still maintain the awestruck wonder of a kinder planting beans pressed against the side of a jar so that the roots, hypocotyl, and plumule display, then watch in amazement as they burst through the ground and struggle toward the light.

    "Hey, Matt. Sure is a gorgeous day to get drunk and throw beanbags back and forth on the front sidewalk for 11 hours!"

  • Roots - the swollen root-hypocotyl is rich in starch and sugars and can be creamy-yellow or light or dark purple in colour; yellow ones are usually the most popular.

    Chapter 23

  • Below the ground the central axis is a fleshy structure consisting of the swollen tap root and hypocotyl, similar in general shape to a globe salad radish, but ending in a thick strong root with numerous lateral rootless.

    Chapter 23

  • Isolation and identification of a new growth inhibitor, Raphanusanin, from radish seedlings and its role in light inhibition of hypocotyl growth.

    Chapter 27

  • The hypocotyl region of affected plants is usually constricted, with black necrotic lesions at soil level.

    Chapter 7

  • Bean with one cotyledon removed, after sprouting had begun. _a_, Seed-coat; _b_, cotyledon; _c_, epicotyl; _d_, hypocotyl; _e_, endosperm.

    The First Book of Farming

  • This is the epicotyl, and another growing tip pointed toward the lower end of the kernel; this is the hypocotyl or the part which penetrates the soil and forms roots.

    The First Book of Farming

  • After sending down a root the hypocotyl began to develop into a strong stem which crooked itself until it reached the surface of the soil and then pulled the cotyledons or seed-leaves after it (Fig. 42).

    The First Book of Farming


Log in or sign up to get involved in the conversation. It's quick and easy.