OBSERVATIONS ON THE CHARACTERISTICS OF THE LEMMA AND PALEA OF THE LATE CENOZOIC GRASS PANICUM ELEGANS
作者:
Joseph R. Thomasson,
期刊:
American Journal of Botany
(WILEY Available online 1978)
卷期:
Volume 65,
issue 1
页码: 34-39
ISSN:0002-9122
年代: 1978
DOI:10.1002/j.1537-2197.1978.tb10831.x
出版商: Wiley
数据来源: WILEY
摘要:
Scanning electron microscopy (SEM) was used to study the surface features of the anthoecia (fertile lemma and palea) ofPanicum elegansElias from the Late Cenozoic deposits in Ellis County, Kansas. Examination of the lemma revealed a well developed germination lid, irregularly arranged, simple, rounded papillae and a crescent‐shaped scar of attachment. The presence of a germination lid indicates that this structure has been present in some members of the Gramineae since at least the Late Miocene‐Early Pliocene. Evidence is presented which contradicts current ideas regarding the distribution of the germination lid in extant Gramineae. The surface of the palea is characterized by simple, rounded papillae spaced in regular rows. The arrangement and form of these papillae are like that present in some modernDichanthelium.Both the epidermises of the lemma and palea are composed entirely of long cells with strongly sinuous, interlocking cell walls. The pattern of cells on the lemma indicates that the systematic placement ofPanicum elegansis correct.
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