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1. The outermost layer of the wall of certain spores.
2. An asexual spore developed externally by budding, as from a sporophore.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Botany) the outer layer of the spores of some algae and fungi
ˌexoˈsporous adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈɛk səˌspɔr, -ˌspoʊr)

the outer coat of a spore.
ex`o•spor′ous, adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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Sporoderm is 4 [micro]m thick, formed by perispore and exospore. Perispore is microrugulate with rugulae homogenously distributed; it is adhered to exospore in young spores but tends to detach; detaching usually begins at the laesure zone in mature spores.
Micromorphology of outer exospore coatings in Selaginella megaspore.
l'exospore chez les Pteridophytes (ultrastructural data of the
Mature spores have a dense exospore coat, a pale endospore, and single rows of 8-11 polar tubule coils (Figure 2, panels B, C).
The spores ranged from 1.4 to 2.4 urn in length and were characterized by an outer electron-dense exospore and a thick electron-lucent endospore.
Braun, the pattern is similar, but the term "outer exospore" is used instead of "paraexospore" (Uehara et al., 1991).
These changes are: #20, quadriseriate branching of axes/leaves absent [right arrow] throughout; #28, stele with radiating arms of xylem absent [right arrow] as rounded lobes; #41, radial axis/rachis trace round-elliptical [right arrow] lobed; #46, position of protoxylem in rachis/axis toward no face [right arrow] toward several faces; and #88, exospore surface nearly smooth or plain [right arrow] obviously sculptured.
[57] found that exospores secreted by MSCs similarly reduced myocardial schema/reperfusion (I/R) injury in mice.
68 of length 9: Aserinsky (family name, OED), ater-miner, afternoons, aucthores, avengings, axenfelds (eye problem), brimmings, bucklings, bydweller, Cogglesby (proper noun, OED savage), crepillit, cwelleras, Dominguez (personal name), drillings, drinkings, duellings, duffields (type of cloth, OED half-thick), dweller by, dwellings, dwillings, exospores (OSPD), frillings, fumositez (c 1400 q, OED original), grillings, grimoires, grip-knobs, Posht-e Waz (Afghanistan) 8 of length 10: ascriptive, aucthorite, aucthorize, by-drinking, Emi Klingue (Libya)
Whittenbury R, Davies SL, Davey JF (1970) Exospores and cysts formed by methane utilising bacteria.