Wood and bark anatomy of Centella: scalariform perforation plates support an affinity with the subfamily Mackinlayoideae (Apiaceae)

作者：Oskolski A A^*; Van Wyk B E

来源：Plant Systematics and Evolution, 2010, 289(3-4): 127-135.

DOI：10.1007/s00606-010-0338-6

• Apiaceae
• Apiopetalum
• Araliaceae
• Bark anatomy
• Centella
• Mackinlaya
• Phylogeny
• Wood anatomy

Detailed descriptions of the wood and bark anatomy of five representative Centella species are presented. The wood structure is reported for the first time for this genus. Scalariform perforation plates occur frequently in the secondary xylem of two Centella species (Centella difformis and C. rupestris) indicating a phylogenetic relationship with Apiopetalum and Mackinlaya, the only other genera of Apiaceae where this feature occurs regularly and not merely as an aberration. This character commonly occurs in two other families of Apiales, Araliaceae and Myodocarpaceae, supporting the presumed basal position of subfamily Mackinlayoidae within Apiaceae. Surprisingly, no axial secretory canals occur in the secondary phloem of Centella species, apparently a unique feature within the suborder Apiineae, which comprises Araliaceae, Myodocarpaceae, Pittosporaceae, and Apiaceae. Other noteworthy characters of Centella include subepidermal origin of the periderm, tangential expansion of rays in dilated secondary phloem, poorly sclerified or non-sclerified collapsed secondary phloem, small intervessel pits with groove-like sculptures near their apertures, diffuse and marginal axial parenchyma, and a predominance of upright and square cells in the ray composition, all of which may be of value in exploring infrageneric relationships.

• 出版日期2010-11