scleroid

English

Etymology

From sclero- +‎ -oid.

Adjective

scleroid (comparative more scleroid, superlative most scleroid)

1. (botany) Having a hard texture.

   The shells of nuts are scleroid.

   • 1876, Emmanuel Le Maout, ‎Joseph Decaisne, A General System of Botany, page 950:

     This scleroid form , which plays a very important part in the vegetation of Fungi, is only a transitory one; it always proceeds from the filamentous state, and may be compared with the tubers of the Potato, and not with a true subterranean stem; its life is truly latent, and only preserved by the hygrometric nature of its tissue.

   • 1911, William Randolph Taylor, “On the Production of New Cell Formations in Plants”, in Contributions from the Botanical Laboratory of the University of Pennsylvania, page 290:

     The scleroid patches, when present, took no part in the reaction. No new scleroid tissue was produced.

   • 1981, Timothy J. Baroni, A Revision of the Genus Rhodocybe Maire (Agaricales), page 24:

     The walls of these scleroid basidia often reach 1 μm or more in thickness and the walls stain deeply with congo red.

2. (anatomy) thickened.
   • 1953, New York Court of Appeals. Records and Briefs, page 415:

     Did you find his drums were thickened and scleroid ?

   • 1960, ‎Konstantin Ivanovich Skri︠a︡bin, Essentials of Nematodology, page 364:

     Pharyngeal walls thick, scleroid.

Noun

scleroid (plural scleroids)

1. The outermost layer of an eyeball.
   • 1860 September 15, Max Kuechler, “The Present State of Ophthalmoscopy”, in The Medical and Surgical Reporter, volume 4, number 24, page 493:

     This is caused by the scleroid which turns around the optic nerve, and projects somewhat above it, thus forming, when illuminated, the clear scleroidal margin.

   • 1914, Arpad G. Gerster, “On the Fomation of Bone in the Human Penis”, in (Please provide the book title or journal name), page 243:

     Bone had been found in various organs and tissues, including the dura and pia mater, in the scleroid and choroid, in the tonsils, in the thyroid, the lung and pleura and other serous membranes.

   • 1978, Alfred Sherwood Romer, ‎Thomas Sturges Parsons, The Vertebrate Body:

     The scleroid is a complete sphere; choroid and retina are incomplete externally.

2. A plant cell with thick cell walls.
   • 1961, Doklady: Botanical sciences sections - Volumes 136-141, page 15:

     At the end of gall formation isolated scleroids are differentiated in the gall parenchyma, and much more rarely, tracheids and vessels.

   • 2002, Paul W. Syltie, How Soils Work, page 13:

     Clusters of irregularly shaped cells (scleroids) form hard shells , like those of pecans or fruit pits .

   • 2010, Ralph Kirby,T.G. Downing and M.I.El Gohary, Fundamentals of Biochemistry, Cell Biology and Biophysics:

     Scleroids form hard layers in roots, stems and seeds.