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 (ĕk′sēn′, -sīn′)
The outer layer of the wall of a spore or pollen grain.

[ex(o)- + Greek īs, īn-, tendon; see wei- in Indo-European roots.]


(ˈɛksɪn; -aɪn) or


(Botany) botany the outermost coat of a pollen grain or a spore. Compare intine


(ˈɛk sin, -saɪn)

the outer coat of a pollen grain.
[1880–85; perhaps ex-1 + -ine1]
References in periodicals archive ?
Description: Miospore, trilete, amb circular to subcircular, lete distinct, arms of lete never extending 3/4 spore radius, labra well developed, raised, translucent uniform up to 4 m broad, 2 m high, contact area indistinct in few specimens may be masked by dark uniform exinal folds parallel to lete, exine up to 1 m thick, infra punctate to intra punctate, punctae more pronounced and dominant around Y'' marking and equator, compressional folds common usually confined to the distal hemisphere.
The lowest value of exine thickness was characterized by Parthenium integrifolium i.
Stage 4: microspores vacuole with a developed exine wall:
The three families differ from Apiineae in several structural features, including the lack of schizogenous secretory canals (see Plunkett & Lowry, 2001) and their pollen exine texturing, which is usually reticulate in most Apiineae but varies in the three remaining families (Karehed, 2003).
Different parameters used for measurement of pollen were shape and size of pollen, exine thickness, polar diameter, equatorial diameter and P/E ratio.
variations, P: polar diameter, E: equatorial diameter, P/E: Pollen shape, Ex/int: the ratio of exine to the intin, clg: colpus length, clt: colpus width, plg: porus length regarding the poles, plt: porus width regarding the equatorial diameter, plg/plt: porus shape, t: one edge of polar triangle.
Frohnmayer received her bachelor's degree in music from the UO in 1960, studying voice with Exine Bailey and piano with George Hopkins.
Stamens included; filaments complanate, lilac toward the apex, the antepetalous ones adnate to the petals for 6-8 mm, the antesepalous ones free; anther base obtuse-sagittate, apex apiculate, apiculus nigrescent, dorsifixed above the base at 1/3 of its length; pollen globose, diporate, exine psillate; stigma conduplicate-spiral, ellipsoid-capitate, lilac-purple, margins crenulate-lacerate; ovary obconic, trigonous, 8-9 mm long, 6-7 mm in diameter at the apex, white, glabrous, bearing inconspicuous longitudinal sulcus; placentation apical; ovules shortly caudate; epigynous tube inconspicuous, ca.
The glycocalyx and initiation of exine spinules on microspores of Canna.
Absence of callose and tetrads in the microsporogenesis of Pandanus odoratissimus with well-formed pollen exine.
Description: Miospore, trilete, amb circular to sub- circular, highly variable due to folding, Y-mark distinct, rays extending up to 2/3rd of the radius, exine variously folded, laevigate, about 1m thick.
Typical exine patterns, shape, size and the dimensions of pollen grains for each jujube cultivar were determined by using a scanning electron micrograph (SEM).