cotyledon


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

cotyledon

 [kot″ĭ-le´don]
1. any subdivision of the uterine surface of the placenta.
2. irregular convex areas on the chorionic surface of the placenta, consisting of two or more stem villi and their many branch villi; by the end of the fourth month the decidua basalis is almost entirely replaced by the cotyledons.

cot·y·le·don

(kot'i-lē'don),
1.
2. In plants, a seed leaf, the first leaf to grow from a seed.
3. A placental unit.
[G. kotylēdon, any cup-shaped hollow]

cotyledon

/cot·y·le·don/ (kot″ĭ-le´d'n)
1. the seed leaf of the embryo of a plant.
2. any subdivision of the uterine surface of the placenta.

cotyledon

(kŏt′l-ēd′n)
n.
1. Botany A leaf of the embryo of a seed plant, which upon germination either remains in the seed or emerges, enlarges, and becomes green. Also called seed leaf.
2. Anatomy One of the lobules constituting the uterine side of the mammalian placenta, consisting mainly of a rounded mass of villi.

cot′y·le′don·ar′y (-ēd′n-ĕr′ē), cot′y·le′don·al (-ēd′n-əl)(-ēd′n-əs), cot′y·le′do·nous (-ēd′n-əs) adj.

cotyledon

[kot′ilē′don]
Etymology: Gk, kotyledon, cup-shaped
one of the visible segments on the maternal surface of the placenta. A typical placenta may have 15 to 28 cotyledons, each consisting of fetal vessels, chorionic villi, and intervillous space.

cot·y·le·don

(kot'i-lē'dŏn)
1. In plants, a seed leaf, the first leaf to grow from a seed.
2. Irregular convex area of the fetal part of the placenta composed of stem villi.
[G. kotylēdon, any cup-shaped hollow]

cotyledon

  1. a part of the plant embryo in the form of a specialized seed leaf that can be thin and papery, as in the castor oil plant, or can act as a storage organ, as in the broad bean, absorbing food from the endosperm. Sometimes it also functions as a leaf after EPIGEAL germination, as in the runner bean. Some ANGIOSPERMS have one cotyledon per seed (MONOCOTYLEDONS) while others have two (DICOTYLEDONS).
  2. a part of the mammalian placenta on which a tuft of villi occurs, particularly in ruminants.

Cotyledon

African genus of the plant family Crassulaceae; contains bufadienolide, cardiac glycosides; causes krimpsiekte (cotyledonosis). Includes C. orbiculata (C. decusata, C. leucophylla), C. umbilicus (Umbilicus rupestris, navelwort, pennywort). Many species have been reclassified as Tylecodon spp.

cotyledon

1. any subdivision of the uterine surface of the human placenta.
2. discrete elevations of chorioallantoic tissue of the ruminant fetal membranes that adhere intimately with the maternal caruncles to form placentomes. See also caruncle.
References in periodicals archive ?
Induction of somatic embryogenesis and caulogenesis from cotyledons and leaf protoplast-derived colonies of melon (Cucumis melo L.
Some seedlings emerge with the cotyledons rising above the ground and participating for a short while in photosynthesis before they shrivel and fall off.
This herbivory treatment was applied 4 and 21 days after planting into a plastic pot to simulate the extent of cotyledon removal by herbivores before and after the emergence of the first set of true leaves.
Ethylene inhibitors enhanced de novo shoot regeneration from cotyledons of Brassica campestris spp.
Epicotyl Axis of the embryonic plant above the cotyledon, terminating in the apical meristem, sometimes bearing scale leaves.
Scientists use similarities among plants to classify or break down plants into eight characteristics: kind of stem, size of plant, stem growth form, kind of fruit, life cycle, foliage retention, temperature tolerances, and number of cotyledons.
In this context, we have recently extensively examined three different modes of STBM preparation: mechanical dissection of fresh placental vinous tissues; in vitro cultures of vinous explants; and perfusion of single placental cotyledons (15).
In the seedling stage, three variance components contribute to the phenotypic value for cotyledon diameter at emergence in the greenhouse: [Mathematical Expression Omitted], [Mathematical Expression Omitted], and negative [[Sigma].
The objective of this study was to develop an effective regeneration protocol for the hypocotyl and cotyledon node explants of Crambe orientalis var.
For single coty-node explants, seedlings were split in the middle of the hypocotyl- cotyledon junction.
A cross-section of the cotyledon petiole shows a hairy uniseriate epidermis, collenchyma, parenchyma and the double trace.