exospore


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ex·o·spore

(ek'sō-spōr),
An exogenous spore, not encased in a sporangium.
[exo- + G. sporos, seed]

exospore

(ĕk′sō-spôr′)
n.
1. The outermost layer of the wall of certain spores.
2. An asexual spore developed externally by budding, as from a sporophore.

exospore

a type of SPORE formed by MICROORGANISMS by BUDDING, or by the formation of a SEPTUM and FISSION.
References in periodicals archive ?
fused to a thin, flat exospore, and an endospore adjacent to the
of the following layers: perispore, para-exospore, exospore, and
A smooth exospore (E) below abraded perispore (P) is evident.
Eleven character states change on the branch subtending Biscalitheca + Corynepteris: #5, growth form of stem/axis erect [right arrow] rhizomatous; #7, arborescence present [right arrow] absent; #24, scales absent [right arrow] present; #35, protoxylem of stem/axis mesarch [right arrow] exarch; #41, radial rachis/axis trace round-elliptical [right arrow] absent; #57, meio/microsporangium bearing structure unlike vegetative [right arrow] somewhat modified from the vegetative; #61, abaxially attached sporangia absent [right arrow] present; #65, meio/microsporangial grouping absent [right arrow] present; #71, sporangial stalk absent [right arrow] broad; #74, functional annulus absent [right arrow] present; and #88, exospore surface nearly smooth or plain [right arrow] obviously sculptured.
Exospore surface: 0 = nearly smooth or plain; 1 = obviously sculptured.
However, two of these specimens (6510 and 7452) have exceptionally large spores (mean exospore lengths > 40 pm), and thus merit further study.
mochaenum Lamina texture herbaceous intermediate coriaceous Aphlebia present present present Sterile frond length (cm) 4-11 5-10 12-30 Fertile frond length (cm) 11-20 8-20 13-36 Number of pinna pairs per sterile frond 7-16 12-17 14-27 Number of main veins per sterile pinna 5-11 8-10 13-29 Length of the petiole paleae (mm) 2-5 2-3 6-11 Length/width ratio of the petiole paleae 2-4 2-3 5-9 Guard cell length 71-80 60-76 58-69 ([micro]m) Exospore length ([micro]m) 37-42 misshapen 32-35
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.