학술논문

Stem anatomy of neotropical Dioscorea L. (Dioscoreaceae) and its importance to the systematics of the genus
Document Type
Original Paper
Source
Plant Systematics and Evolution. June 2017 303(6):775-786
Subject
Aerial stem
Dioscoreales
Neotropical region
Tylosoids
Vascular bundles
Language
English
ISSN
0378-2697
2199-6881
Abstract
We anatomically characterized the aerial stems of the genus Dioscorea and evaluated the use of these anatomical characteristics to better understand the taxonomy, systematics, and diversity of the component species in the neotropics. Fragments of the aerial stems of 23 species were collected for anatomical analyses utilizing conventional cytohistological techniques. Stem anatomy did not support the subgenera and neotropical sections of Dioscorea, although D. sect. Monadelpha demonstrated similar anatomical characteristics with the representatives analyzed in the present work, supporting the possible monophyletism of that section. Some New World species demonstrated characteristics described earlier for Old World species, such as two phloem units internal to the large-diameter vessels. New characters to the vascularization of new world species are described, as a single ring of vascular bundles, intercalating common and cauline bundles. Tylosoids and actinocytic stomata were the first time reported in Dioscorea, and the vascular patterns are revisited with a systematic approach.