Phytolith analysis of Cyperaceae from the Pampean region, Argentina

FERNÁNDEZ HONAINE, MARIANA; ZUCOL, ALEJANDRO; OSTERRIETH, MARGARITA

AUSTRALIAN JOURNAL OF BOTANY

CSIRO

Año: 2009 vol. 57 p. 512 - 523

0067-1924

Cyperaceae, along with Poaceae, is the main silica accumulator. Although the anatomical-taxonomic andpalaeobotanical relevance of phytoliths has been well established, there are no studies that deal with the qualitative andquantitative aspects of the phytolith production or differentiate phytoliths from the different organs in Cyperaceae. Towardthe construction of a detailed database of phytolith production, we describe in the present paper the phytoliths of leaves,culms and fruits of Cyperaceae from Pampean region (Argentina). Phytoliths were extracted by a calcination technique.Qualitative and quantitative characters and percentages of phytolith morphotypes were subject to principal componentanalysis to analyse their taxonomic relevance. For some sedges, values of phytolith content and a comparative analysis ofleaves, culms and fruit phytoliths are presented here for the first time. Diverse tissues such as epidermis, xylem, parenchymaand sclerenchyma produced phytoliths. Themost abundantmorphotypeswere conical phytoliths,which showed differencesin the base shape and in their size between organs. Leaf/culm cones have a rounded, rectangular or square base; typical fruitcones have a polygonal base and they are bigger andmore robust. PCAshowed that quantitative and qualitative characters ofcones, along with the percentages of morphotypes, allowed group distinction.