Phytoliths in Inflorescence Bracts: Preliminary Results of an Investigation on Common Panicoideae Plants in China

Abstract

Phytoliths in the inflorescence of Poaceae plants can be of high taxonomic value in some archaeological contexts and provide insight into plant taxonomy and crop domestication processes. In this study, phytoliths in every inflorescence bract of 38 common Panicoideae weeds and minor crops in China were studied. Based on dissection of the inflorescence into different bracts using a treatment that retained the phytoliths anatomical position, observations of inflorescence phytoliths types and distribution were described in detail. We found that INTERDIGITATING, Blocky amoeboid, Rectangular dentate, and Elongate dendritic with multi tent-like arch tops were of higher taxonomic value than the other types in our studied species. Both morphological and morphometric traits of the INTERDIGITATING were summarized and compared with previous studies; the findings suggested that genus level discrimination of some Paniceae species could be reliable, and tribe/species level discrimination might be feasible. The phytoliths in the involucre of domesticated and wild type Coix lacryma-jobi provided insight into the domestication process of this plant. Our data also indicated that phytolith production in the inflorescence bracts might be under the genetic and molecular control of inflorescence development. Thus, the findings of this study could assist future studies in plant taxonomy and archaeobotany.

Phytoliths in selected broad-leaved trees in China

“…However, we found that phytolith types and production in species belonging to different genera of the same family can be very different. Such results suggest the possibility of identification of taxa on the genus level using phytolith analysis, which is in consist with the study of grasses 22 , however, studies that involve more species and more samples of species are needed to confirm such findings. To date, no especially diagnostic types of phytoliths have been identified for broad-leaved trees in general or a certain family.…”

“…1-15) which we found in the fruit husk of Aleurites moluccana (which could be used as food or sauce in Malaysia and Indonesia), is also noteworthy as it has not been reported yet. Such silicification in fruit husks might be a protection strategy 22,66 , and the presence of this type may provide insight into ancient plant resource exploitation. In this study, we have provided an illustration of several distinct phytolith types we observed in the common broad-leaved trees in temperate China, and reported that there appears to be little difference in broad-leaved trees phytolith production between the northern and the southern regions.…”

“…1 -15) which we found in the fruit husk of Aleurites moluccana (which could be used as food or sauce in Malaysia and Indonesia), is also noteworthy as it has not been reported yet. Such silicification in fruit husks might be a protection strategy 22 , 66 , and the presence of this type may provide insight into ancient plant resource exploitation.…”

Phytolith evidence for the pastoral origins of multi-cropping in Mesopotamia (ancient Iraq)

“…3 , 4 and Supplementary Tables S3 – 4 ). During phytolith morphological analysis of the sediments from Trench Y82 54 (see Supplementary Text), we encountered phytoliths in anatomical connection, or multicellular structures (also known as silica skeletons 66 or articulated groups 67 ), composed of interdigitating phytolith morphotypes 68 , 69 similar to Panicum miliaceum in ten samples (Table S1 ). In general, phytolith preservation was good across all samples (Supplementary Text) as is typical for archaeological sites (or tells) in Southwest Asia where phytoliths are removed from the silica cycle 70 – 73 .…”

“…In fact, five of the nine genera representing millets and their wild relatives 81 are present in modern Iraq ( Digitaria , Echinochloa, Panicum , Paspalum , Setaria , and Sorghum ) (Supplementary Table S6 ) 17 , 80 . Thus, it is necessary to use at least five diagnostic criteria to ensure secure species-level identifications of millet inflorescence phytoliths (Supplementary Table S5 ) 68 , 75 – 77 , 82 . Like phytoliths from grass inflorescences, bilobate short cells can be used to distinguish between domesticated millet species 83 .…”