TY - JOUR
T1 - Vessels of Illicium (Illiciaceae)
T2 - Range of pit membrane remnant presence in perforations and other vessel details
AU - Carlquist, Sherwin
AU - Schneider, Edward L.
PY - 2002/9
Y1 - 2002/9
N2 - Scanning electron microscope (SEM) examination of vessels from radial sections of Illicium wood showed a wide range of pit membrane remnant presence within any given species and within the seven species studied here. Earlier studies showed that dried specimens offer a reliable indicator of pit membrane presence. In all species, wide variation occurs, from intact pit membranes to perforations virtually free of pit membrane remnants. Illicium parviflorum has the largest number for the genus of perforation plates, with little or no pit membrane presence, although, in some plates, appreciable pit membrane presence was evident. Species differ in the forms taken by the pit membrane remnants: threads running axially in the perforations are common, but weblike conformations or pit membranes perforated by small circular to oval pores are other commonly encountered conditions. Artifacts attributable to handling and other factors are analyzed to obtain an image of pit membrane presence. Pit membrane remnant presence is consistent with the presence of other strongly primitive features of Illicium and its near-basal position in phylogenetic trees based on molecular data. Unusually narrow and sparse helical thickenings are figured with SEM for the genus for the first time; these thickenings occur in three species from habitats in which winter freezing occurs.
AB - Scanning electron microscope (SEM) examination of vessels from radial sections of Illicium wood showed a wide range of pit membrane remnant presence within any given species and within the seven species studied here. Earlier studies showed that dried specimens offer a reliable indicator of pit membrane presence. In all species, wide variation occurs, from intact pit membranes to perforations virtually free of pit membrane remnants. Illicium parviflorum has the largest number for the genus of perforation plates, with little or no pit membrane presence, although, in some plates, appreciable pit membrane presence was evident. Species differ in the forms taken by the pit membrane remnants: threads running axially in the perforations are common, but weblike conformations or pit membranes perforated by small circular to oval pores are other commonly encountered conditions. Artifacts attributable to handling and other factors are analyzed to obtain an image of pit membrane presence. Pit membrane remnant presence is consistent with the presence of other strongly primitive features of Illicium and its near-basal position in phylogenetic trees based on molecular data. Unusually narrow and sparse helical thickenings are figured with SEM for the genus for the first time; these thickenings occur in three species from habitats in which winter freezing occurs.
KW - Basal angiosperms
KW - Ecological wood anatomy
KW - Illiciales
KW - Perforation plates
KW - Primitive wood features
KW - Vessel evolution
KW - Wood evolution
KW - Xylem
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UR - http://www.scopus.com/inward/citedby.url?scp=0036720553&partnerID=8YFLogxK
U2 - 10.1086/342080
DO - 10.1086/342080
M3 - Article
AN - SCOPUS:0036720553
SN - 1058-5893
VL - 163
SP - 755
EP - 763
JO - International Journal of Plant Sciences
JF - International Journal of Plant Sciences
IS - 5
ER -