Phytoliths from some grasses (Poaceae) in arid lands of Xinjiang, China

Abstract

Opal phytoliths, as silicon dioxide inclusions, are abundant in different parts of a plant. It is known that grasses are the most representative in this respect. The research of phytoliths, removed from 25 most common grass species in the arid and semiarid lands of the Junggar Basin and adjacent areas, has been undertaken. The visual estimation of diversity and variability of silica cells and identification of their morphological types (patterns) were also the aim of our research. Since the work is preliminary, we have emphasized on the visual estimation of silica cell variability and involved only the leaf blades in the analysis. Drawings of the revealed silica cells, characteristic of 25 species, are provided. The sig-nificant morphological diversity of phytoliths has been revealed, as well as their taxonomic similarity at the level of subfamilies. These data can be used for the identification of phytoliths from sediments.

Full text

Phytoliths from some grasses (Poaceae)
in arid lands of Xinjiang, China
Marina V. Olonova1, Polina D. Gudkova1, 2,
Valeria D. Shiposha1, Elizaveta A. Kriuchkova2,
Natalia S. Mezina1, Mikhail Blinnikov3
1 Tomsk State University, Biological Institute, 36 Lenin av., Tomsk, 634050, Russia
2 Altai State University, 61 Lenin av., Barnaul, 656049, Russia
3 St. Cloud State University, Department of Geography and Planning, St. Cloud, Minnesota,
56301-4498, USA
Corresponding author: Marina V. Olonova (olonova@list.ru)
Academic editor: R. Yakovlev|Received 8 October 2021|Accepted 5 November 2021|Published 16 November 2021
http://zoobank.org/077C4A6F-F518-4696-A2F7-0D970F99B904
Citation: Olonova MV, Gudkova PD, Shiposha VD, Kriuchkova EA, Mezina NS, Blinnikov M (2021) Phytoliths
from some grasses (Poaceae) in arid lands of Xinjiang, China. Acta Biologica Sibirica 7: 345–361. https://doi.
org/10.3897/abs.7.e76105
Abstract
Opal phytoliths, as silicon dioxide inclusions, are abundant in dierent parts of a plant. It is known
that grasses are the most representative in this respect. e research of phytoliths, removed from 25
most common grass species in the arid and semiarid lands of the Junggar Basin and adjacent areas, has
been undertaken. e visual estimation of diversity and variability of silica cells and identication of
their morphological types (patterns) were also the aim of our research. Since the work is preliminary,
we have emphasized on the visual estimation of silica cell variability and involved only the leaf blades
in the analysis. Drawings of the revealed silica cells, characteristic of 25 species, are provided. e sig-
nicant morphological diversity of phytoliths has been revealed, as well as their taxonomic similarity
at the level of subfamilies. ese data can be used for the identication of phytoliths from sediments.
Keywords
Central Asia, deserts, plant anatomy, silicon dioxide inclusion
Acta Biologica Sibirica 7: 345–361 (2021)
doi: 10.3897/abs.7.e76105
https://abs.pensoft.net
Copyright Marina V. Olonova et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC
BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
RESEARCH A RTICLE

346Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
Introduction
Increasing attention of contemporary science is given to the study of phytoliths.
Phytoliths are silicon dioxide inclusions abundant in dierent parts of a plant. Sili-
con, being dissolved in underground water, can be adsorbed by plants, and then it
is deposited between the cell walls as opal. It can impregnate the cellular walls or
ll the plant cells completely and may be dispersed in leaves, roots, stems, and even
seeds. As for grasses, they are concentrated mainly in the epidermis (Krishnan et
al. 2000). e phytoliths increase the plant density, support the vertical position of
stems, promote the absorption of sunlight for photosynthesis, serve as protection
against fungal infection, and also make plants less attractive to herbivores, rodents,
and insects (Lu et al. 2002; Lu and Liu 2003a; Myrlian and Medyanik 2008).
During the last 30 years, grass phytoliths together with pollen grains, are widely
used for stratication, as well as paleobotanical and paleogeographic reconstruc-
tions (Witty et al. 1964; Kurmann 1985; Fisher et al. 1995; Blinnikov 2005). In fact,
grass phytoliths have a number of advantages over pollen grains in terms of their
use in paleogeography. Being composed of silicon, phytoliths are more resistant to
destruction than pollen or spores of vascular plants. eir inorganic origin makes
them denser than organic remains. ey have a greater density than other fossils of
plants and keep their morphological features aer the plant dies o. Phytoliths are
transferred by winds or water streams much less than pollen grains, and they usu-
ally remain and deposit near a parent plant aer decomposition (Myrlian and Me-
dianic 2008). Pollen grains usually do not vary signicantly in their shapes, whereas
phytoliths essentially vary both in their sizes and shapes, corresponding to certain
plants taxa, and help to date the time of grass diversication (Stromberg 2004) and
vegetation of past epochs. Phytoliths are successfully used in paleoclimatology
(Twiss 1987; Liu et al. 1995; Lu et al. 2006), paleogeography, and soil science (Wu
et al. 1992; Golyeva 1995; Contreras et al. 2019). Besides, phytoliths, found in the
sediments of archeologic sites, are applied to dene agricultural and cattle-breading
activities of ancient people and to identify plants used by people in ancient and pre-
historic periods (Elbaum et al. 2003; Delhon 2008; Piperno 2006; Wang et al. 2018;
Danu et al. 2019). Indeed, in accordance with Rosen et al. (2008), phytolith analysis
is one of the most versatile archaeobotanical techniques used in archaeology and
paleoenvironmental analysis. Besides listing the most common ways of uses of phy-
toliths, they mentioned some less traditional ones, such as the evidence for both
natural and human-induced re ecology by distinguishing phytoliths from burned
material versus those from unburned deposits; analysis of phytolith properties in-
dicating irrigation agriculture in alluvial valleys versus dry-farming in interuvial
settings; reconstructing climatic records from carbon and oxygen isotopes found
respectively within organic matter occluded inside phytoliths, and oxygen from the
SiO₂ itself. Regardless of the fact that phytoliths of many grasses are quite similar,
they can be used successfully for vegetation reconstructions and specication of
oristic characteristics (Patterer et al. 2013). Piperno (1988) has underlined that

Phytoliths from grasses in arid lands of Xinjiang, China 347
genus level identication is not necessary for accurate and informative reconstruc-
tions of grass ecosystems. Many researchers (Golyeva 1995; Blinnikov 2005; Neto et
al. 2018) use the whole phytolith complexes, which serve as indicators of dierent
phytocenosis, for stratication, dating, and reconstruction of vegetation changes.
e aim of our research was a preliminary visual estimation of phytolith types
and their diversity in investigated species, to reveal the specic morphological types,
corresponding to certain taxa of grasses, and to make the special tables of phytoliths
types of these species. We have undertaken an attempt to extract phytoliths from
leaves of 25 most common grass species in the arid and semiarid lands of the Jung-
gar Basin and adjacent areas of Xinjiang, China. Since the work is preliminary, we
investigated only the leaf blades and have emphasized on the visual estimation of
silica cell variability. ese results can be used for the identication of phytoliths
from sediments. e phytoliths complexes usually used for vegetation reconstruc-
tions, consist of phytoliths of dierent plant species. e more species are involved
in the study and the better phytolith research is carried out, the more reliable the
reconstructions will be.
Material and methods
e study area covers the Northern part of Xinjiang province (Fig. 1), approximate-
ly between 45–48° N and 86–90° E and is characterized by elevations failing within
(-83) 300–600 m (Table 1), where dry arid climate take place (Lo 1957; Zhan et al.
1957). Murzayev (1966) shows the annual mean temperature for this area 6–8 °C,
(average temperature of July 24–26 (34) °C, January 18–20 °C below zero) and an-
nual precipitation (50) 100–300 mm. It caused the formation of dry steppes and
deserts there (Hou 1988; Ni 2001), where arid grasses are common. Nevertheless,
due to the high diversity of habitats, species that are common in semiarid com-
munities may occur also in deserts, when meeting the appropriate conditions. is
territory was chosen on the one side, because being rich in grasses of dierent sub-
families, and phytoliths of dierent systematic groups could be extracted and com-
pared. On the other side, because the arid and semiarid lands are quite common
there, it was possible to identify the main types of grass phytoliths, characteristic
for plant communities of arid and semiarid territories. Grasses were collected in
the summer of 2010 by M. Olonova and Duan Shimin in arid and semiarid plant
communities (TK). e map was constructed using ArcGIS soware (ESRI, 2012).
A total of 25 grass species (52 samples) have been studied. All selected samples
were in a phase of owering, with well-developed ag leaves and similar morpho-
logical type of species. e stems and leaves were studied.
Samples are stored in the Herbarium of Tomsk State University (TK). ree to
ve individuals were selected from each population. e phytoliths were removed
from leaves by the method of Piperno (1988). e samples were placed in porcelain
crucibles, then into a mue furnace, and ignited at 500 °C for 2 hours. en they

348Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
were allowed to cool and washed with 10% HCl, concentrated nitric acid, and nally
distilled water. e phytoliths were placed in glass bottles and then were examined
under a microscope and photographed. e research of silica cells was carried out
by means of a hardware-soware complex SIAMS MesoPlant, which includes a spe-
cialized computer, microscope Axiostar, the scanner, and digital video camera SIM-
AGIS 2M-75. e epidermis of all samples was observed in a light microscope in
order to have a notion about its construction.
e morphological types of phytoliths were recognized in accordance with the
classication of Powers-Jones and Padmore (1993) and Lu and Liu (2003b). e rec-
ommendations, stated in the International Code of the Nomenclature of Phytoliths
(Madella et al. 2005) have been taken into account as well.
Table 1. e samples, used for phytoliths extraction (TK)
№ Species Location
1Stephanachne pappophorea Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, on the dry brook bed, 08.09.2010. M.
Olonova, Duan Shimin (TK)
2Piptatherum songaricum
(Trin. et Rupr.) Roshev.
Сhina, Xinjiang, Irtysh river head, N 47°12', E 89°49', stony
steppe slope, 09.09.2010. M. Olonova, Duan Shimin (TK)
3Piptatherum songaricum Сhina, Xinjiang, near Altai Forest park, N 47°57', E 88°11',
stepped slope, 10.09.2010. M. Olonova, Duan Shimin (TK)
4Piptatherum songaricum Сhina, Xinjiang Altai mountains, N 48°38', E 87°02', stepped
slope, 10.09.2010. M. Olonova, Duan Shimin (TK)
5Stipa sareptana Сhina, Xinjiang, near Altay, N 47°58' E 88°11', steppe desert,
10.09.2010. M. Olonova, Duan Shimin (TK)
6Stipa glareosa Сhina, Xinjiang, near Altay, N 47°58' E 88°11', steppe desert,
10.09.2010. M. Olonova, Duan Shimin (TK)
7Stipa glareosa Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, 08.09.2010. M. Olonova, Duan
Shimin (TK)
8Stipa glareosa Сhina, Xinjiang, Altai mountains, N 47°12', E 89°48' steppe
desert, 10.09.2010. M. Olonova, Duan Shimin (TK)
9Ptilagrostis pellioti Сhina, Xinjiang, along the road Urumqi – Turpan, near
wind power-station, shrub desert, 2.10.2010. M. Olonova,
Duan Shimin (TK)
10 Achnatherum splendens
(Trin.) Nevski
Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, 08.09.2010
11 Achnatherum splendens Сhina, Xinjiang, along the road Urumqi – Fuyun, N 47°12',
E 89°48', steppe desert, 09.09.2010. M. Olonova, Duan
Shimin (TK)
12 Achnatherum splendens Сhina, Xinjiang, bank of Irtysh river, near the bridge,
N 47°52', E 89°17', rocky steppe desert, 12.09.2010. M.
Olonova, Duan Shimin (TK)

Phytoliths from grasses in arid lands of Xinjiang, China 349
№ Species Location
13 Achnatherum сaragana
(Trin.) Nevski
Сhina, Xinjiang, near Altay, N 47°58' E 88°11', steppe desert,
10.09.2010. M. Olonova, Duan Shimin (TK)
14 Achnatherum сaragana Сhina, Xinjiang, Altay mountains, N 47°51', E 88°12' steppe
desert on the top of the mountain, 10.09.2010. M. Olonova,
Duan Shimin (TK)
15 Achnatherum сaragana Сhina, Xinjiang, N 47°33', E 88°25', steppe desert,
13.09.2010
16 Melica transilvanica Сhina, Xinjiang, Irtysh river head, N 47°12', E 89°49', stony
stepped slope, 09.09.2010. M. Olonova, Duan Shimin (TK)
17 Melica transsilvanica Сhina, Xinjiang, near Altai Forest park, N 47°57', E 88°11',
stepped slope, 10.09.2010. M. Olonova, Duan Shimin (TK)
18 Melica transsilvanica Schur Сhina, Xinjiang Altai mountains, N 48°38', E 87°02', stepped
slope, 10.09.2010. M. Olonova, Duan Shimin (TK)
19 Polypogon monspeliensis
(L.) Desf.
Сhina, Xinjiang, bank of Irtysh River, near the bridge,
N 47°52', E 86°17', steppe desert, among the shrubs,
12.09.2010. M. Olonova, Duan Shimin (TK)
20 Bromus squarrosus L. Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, among the shrubs, 08.09.2010. M.
Olonova, Duan Shimin (TK)
21 Bromus squarrosus Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, on the dry brook bed, 08.09.2010. M.
Olonova, Duan Shimin (TK)
22 Bromus squarrosus Сhina, Xinjiang, bank of Irtysh River, near the bridge,
N 47°52', E 86°17', steppe desert, among the shrubs,
12.09.2010. M. Olonova, Duan Shimin (TK)
23 Leymus racemosus (Lam.)
Tzvel.
Сhina, Xinjiang, N 48°21'N, E 85°45', sandy desert,
12.09.2010. M. Olonova, Duan Shimin (TK)
24 Leymus racemosus Сhina, Xinjiang, along the road Urumqi – Fukang, sandy
desert, 08.09.2010. M. Olonova, Duan Shimin (TK)
25 Leymus secalinus (Georgi)
Tzvel.
Сhina, Xinjiang, Irtysh River head, N 47°12', E 89°49', stony
stepped slope, 09.09.2010. M. Olonova, Duan Shimin (TK)
26 Leymus secalinus Сhina, Xinjiang, near Altai Forest park, N 47°57', E 88°11',
stepped slope, 10.09.2010. M. Olonova, Duan Shimin (TK)
27 Psathyrostachys juncea Сhina, Xinjiang, near Altay, N 47°58' E 88°11', steppe desert,
10.09.2010. M. Olonova, Duan Shimin (TK)
28 Psathyrostachys juncea Сhina, Xinjiang, Altai mountains, N 47°12', E 89°48',
stepped desert, 10.09.2010. M. Olonova, Duan Shimin (TK)
29 Psathyrostachys juncea Сhina, Xinjiang, Irtysh river head, N 47°12', E 89°49',
stepped desert on the slope, 09.09.2010. M. Olonova, Duan
Shimin (TK)
30 Kengyilia hirsuta Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, among the shrubs, 08.09.2010. M.
Olonova, Duan Shimin (TK)
31 Kengyilia kokonorica Сhina, Xinjiang, along the road Urumqi – Turpan, near
wind power-station, rocky desert, among the shrubs,
2.10.2010. M. Olonova, Duan Shimin (TK)

350Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
№ Species Location
32 Eremopyrum bonaepartis
(Spreng.) Nevski
Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, 08.09.2010. M. Olonova, Duan
Shimin (TK)
33 Schismus arabicus Nees Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, on the dry brook bed, 08.09.2010. M.
Olonova, Duan Shimin (TK)
34 Schismus arabicus Сhina, Xinjiang, along the road Urumqi – Fuyun, N 47°12',
E 89°48', steppe desert, 09.09.2010. M. Olonova, Duan
Shimin (TK)
35 Schismus arabicus Сhina, Xinjiang, Turpan, near Turpan Botanical garden,
along the water canal, 2.10.2010. M. Olonova, Duan Shimin
(TK)
36 Aristida adscensionis L. Сhina, Xinjiang, Near Turpan, sandy desert, 2.10.2010. M.
Olonova, Duan Shimin (TK)
37 Aristida adscensionis Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', sandy desert, 08.09.2010. M. Olonova, Duan
Shimin (TK)
38 Aristida adscensionis Сhina, Xinjiang, along the road Urumqi – Fukang, sandy
desert, 08.09.2010. M. Olonova, Duan Shimin (TK)
39 Stipagrostis pennata (Trin.)
de Winter
Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', sandy desert, 08.09.2010. M. Olonova, Duan
Shimin (TK)
40 Stipagrostis pennata Сhina, Xinjiang, N 48°21', E 85°45', sandy desert,
12.09.2010. M. Olonova, Duan Shimin (TK)
41 Stipagrostis pennata Сhina, Xinjiang, N 48°03', E 85°39', sandy desert,
12.09.2010. M. Olonova, Duan Shimin (TK)
42 Aeluropus micrantherus Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, on the dry brook bed, 08.09.2010. M.
Olonova, Duan Shimin (TK)
43 Aeluropus pungens Сhina, Xinjiang, bank of Irtysh River, near the bridge.
E 47°52', E 89°17', rocky steppe desert, 12.09.2010. M.
Olonova, Duan Shimin (TK)
44 Cleistogenes squarrosa
(Trin.) Keng
Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, 08.09.2010. M. Olonova, Duan
Shimin (TK)
45 Cleistogenes squarrosa Сhina, Xinjiang, Altay mountains, N 47°51', E 88°12',
stepped desert on the top of mountain, 09.09.2010. M.
Olonova, Duan Shimin (TK)
46 Cleistogenes squarrosa Сhina, Xinjiang, along the road Urumqi – Turpan, near
wind power-station, rocky desert, 2.10.2010. M. Olonova,
Duan Shimin (TK)
47 Crypsis schoenoides Сhina, Xinjiang, bank of Irtysh River, near the bridge,
N 47°52', E 89°17', rocky steppe desert, 12.09.2010. M.
Olonova, Duan Shimin (TK)
48 Crypsis schoenoides Сhina, Xinjiang, Turpan Botanical garden, among the trees,
2.10.2010. M. Olonova, Duan Shimin (TK)

Phytoliths from grasses in arid lands of Xinjiang, China 351
№ Species Location
49 Chloris virgata Сhina, Xinjiang, along the road Urumqi – Turpan, near
wind power-station, shrub desert, 2.10.2010. M. Olonova,
Duan Shimin (TK)
50 Chloris virgata Сhina, Xinjiang, Turpan, near Turpan Botanical garden,
along the road, 2.10.2010. M. Olonova, Duan Shimin (TK)
51 Chloris virgata Сhina, Xinjiang, along the road Urumqi – Fuyun, N 45°05',
E 89°16', rocky desert, on the dry brook bed, 08.09.2010. M.
Olonova, Duan Shimin (TK)
52 Bothriochloa ischaemum Сhina, Xinjiang, Altay mountains, N 47°51', E 88°12', steppe
desert on the top of mountain, 10.09.2010. M. Olonova,
Duan Shimin (TK)
53 Bothriochloa ischaemum Сhina, Xinjiang, near Altai Forest park, N 47°57', E 88°11',
stepped slope, 10.09.2010. M. Olonova, Duan Shimin (TK)
54 Bothriochloa ischaemum Сhina, Xinjiang, Turpan Botanical garden, among the trees,
2.10.2010. M. Olonova, Duan Shimin (TK)
Figure 1. Map of the study area (Сhina, Xinjiang).

352Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
Results and discussion
It is known that most grasses have a dierent epidermal structure between the veins
of leaf blades and the rest of the area. e cells at the veins (costal zone) are usually
shorter and narrower, and dierent kinds of trichomes are common there and sto-
mata are usually absent (Metcalfe 1960). In the area between veins (intercostal zone)
the cells are usually larger and longer, and the stomata are located here. e research
has revealed the cells of both areas, impregnated with silicon, but the cells from
veins are prevailing (Olonova et al. 2016). e short cells, which are also referred to
as silica bodies, are of major importance in phytolith analysis because their shapes
are known to be eectively conjoined with dierent subfamilies.
e study of morphological types of phytoliths, removed from these species,
has revealed their great diversity, both in size and in shape, corresponded to their
taxonomic variability. Altogether, 12 types of phytoliths have been registered (Ta-
ble 2), but, since all of them seem to represent a continual sequence, the accepted
division is quite relative: some of the types might be divided, and to other of them
might be jointed; irregular phytoliths might be recognized among polylobate ones
as well. Nevertheless, it can give a notion about phytolith diversity. e main task
may hence be considered to have been fullled. Dierent types of phytoliths have
been registered. ere were rod, saddle, roundel, square, trapezoid, triangular, and
prickles as well. Polylobate, saddle, and bilobate proved to be the most variable.
Table 2. Morphological types of phytoliths from some grasses in arid and semiarid lands
of Xinjiang.
Taxa Morphotype of phytoliths (see Fig. 2)
1 2 3 4 5 6 7 8 9 10 11 12
Pooideae
Stephanachne pappophorea - - - b a b - a a a - a
Piptatherum songaricum - b - b, d - c - - - - - -
Stipa sareptana - - - - c h - a - a - a, b
Stipa glareosa - a - - - - - a a a - b
Ptilagrostis pellioti - - - - - - - a a a a a
Achnatherum splendens - a - - - - - a - - - -
Achnatherum caragana - - - c a, b h - a a - a a
Melica transsilvanica - a - c b - - a a a a a
Polypogon monspeliensis - a, b - a c - - - - - a a
Bromus squarrosus a a - - b - - a - - - -
Leymus racemosus - - - - b - - a - a - -
Leymus secalinus - a - - a, b - - - a a - a
Psathyrostachys juncea - - - b a, c e, b - a - - - a

Phytoliths from grasses in arid lands of Xinjiang, China 353
e single investigated representative of subfamily Panicoideae Link, Botrioch-
loa ischaemum (L.) Keng, has proved to possess the most singular silica cells. e
long cells with narrow and long folds (Fig. 2) have been found only among samples
of this species (Fig. 3Y). Various lobate silica cells, including polylobate, turned to
bilobate and then transformed to four-lobed characteristics for this species as well.
e quadra-lobate type never occurred in others. Some similar phytoliths have been
found at Aeluropus Trin. (subfamily Chloridoideae). Nevertheless, they cannot be
recognized as exactly quadra-lobate (Fig. 3T).
e phytoliths of Сleistogenes squarrosa (subfamily Chloridoideae) as a whole,
diered from those of all other investigated samples, being represented mainly by
various kinds of bilobate cells (Figs 3V, 4). e predominance of various bilobate
phytoliths was characteristic for all investigated Chloridoideae Kunth ex Beilschm.,
but the presence of the form with the elongated middle part (Fig. 2), besides being
found at Сleistogenes Keng, was registered only among the samples of Aristida ad-
scensionis (subfamily Aristideae C.E. Hubb.).
All samples of Aristida adscensionis contained bilobate cells (or dumbbells) of
almost the same size, which are characteristic for an intercostal zone, small ron-
Taxa Morphotype of phytoliths (see Fig. 2)
1 2 3 4 5 6 7 8 9 10 11 12
Kengyilia hirsuta - a - b a b - a a a - a
Kengyilia kokonorica a a - c b b - a - a a a
Eremopyrum bonaepartis a a, b - - b d - a - - - a
Danthonioideae
Schismus arabicus - b - a, b, c b, d e - - a - - a
Aristideae
Aristida adscensionis - a - - c, d e, f - a a a - a
Stipagrostis pennata - a - b - e - - a - - a
Chloridoideae
Aeluropus micrantherus - - - - b, b, h - - - - a a
Aeluropus pungens - b - - b b, h - - a - a a
Cleistogenes sqarrosa - - - - - b, e,
f, g
- a - - - a
Crypsis schoenoides - a - - b, d b, d - - - a - a
Chloris virgata - b - - a, d - - - - - - a
Panicoideae
Bothryochloa ischaemum - b a - - a, d a - - - - -
Type of phytoliths: 1 – Smooth rods. 2 – Narrow wavy rods. 3 – Coarse wavy rods. 4 – Poly-
lobate. 5 – Saddle. 6 – Bilobate. 7 – Quadra-lobate. 8 – Rondel. 9 – Square. 10 – Trapezoid.
11 – Triangular. 12 – Prickles. Symbols a, b, c, d, e, f, g, h denote the same as in Figure 2.

354Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
Figure 2. Morphological types of phytoliths from some grasses of arid lands of Xinjiang.
dels (orbicular), square cells, the cells of intermediate type, and pricles (Fig. 3R). A
small amount of coarse wavy rods and polylobates have been found as well. At other
species of this subfamily – Stipagrostis pennata– saddle phytoliths were prevailing,
whereas bilobate ones were rarely found (Fig. 3S).
Phytoliths of Schismus arabicus at the single investigated representative of sub-
family Danthonioideae N.P. Barker et H.P. Linder, have no unique or distinctive
attributes (Fig. 3Q). e coarse wavy rods, polylobate, and saddle types were pre-
dominant ones in all samplings of this species, the last type to be rather intermedi-
ate between the typical saddle and polylobate (Fig. 2).

Phytoliths from grasses in arid lands of Xinjiang, China 355
Figure 3. Morphological types of phytoliths from some grasses of arid lands of Xinjiang
(scale line 250 mkm). A – Stephanachne pappophorea; B – Piptatherum songaricum; C –
Stipa sareptana; D – Stipa glareosa; E – Ptilagrostis pellioti; F – Achnatherum splendens; G
– Achnatherum caragana; H – Melica transsilvanica; I – Polypogon monspeliensis; J – Bromus
squarrosus; K – Leymus racemosus; L – Leymus secalinus; M – Psathyrostachys juncea; N –
Kengyilia hirsuta; O – Kengyilia kokonorica; P – Eremopyrum bonaepartis; Q – Schismus
arabicus; R – Aristida adscensionis; S – Stipagrostis pennata; T – Aeluropus micrantherus; U
– Aeluropus pungens; V – Cleistogenes sqarrosa; W – Crypsis schoenoides; X – Chloris virgate;
Y – Botriochloa ischaemum.

356Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
Figure 4. Phytoliths of some grasses of the arid area of Xinjiang.
Subfamily Pooideae Benth. is not only the best presented in this research, but
also most various in taxonomic respect. e samples of 5 tribes, belonging to this
subfamily, have been involved in this analysis (Table 1). e phytoliths, removed
from these species, are very various and diverse (Figs 3, 4). ere are notable dis-
tinctions in structure and proportion of phytoliths at a tribe level also.

Phytoliths from grasses in arid lands of Xinjiang, China 357
Tribe Stipeae Dumort. seems to be the most singular among subfamily Pooi-
deae, and in the shape of its silica cells, it is quite similar to subfamily Chloridoideae.
It is the most noticeable at Piptatherum songaricum, whose phytoliths are presented
by regular, bead-formed polylobate silica cells, which were then reduced to bilobate
ones (Figs 3B, 4). e polylobate and bilobate phytoliths are not characteristic for
subfamily Pooideae, nevertheless the similar cells occur at Achnatherum caraganа
(Fig. 3G), whereas, at the close species, Achnatherum splendens roundel (orbicular)
silica cells, more typical for this subfamily, prevailed (Fig. 3F; Table 2).
In the tribe Triticeae Dumort., the most singular are the rod-formed phytoliths,
resembling the narrow wavy rods (Figs 2, 3). ey were revealed at Eremopyrum
bonaepartis (Fig. 3P), Kengyilia kokonorica (Figs 3O, 4). e rod-formed silica cells
of other species of this tribe had almost smooth walls – Psathyrostachys juncea (Figs
3M, 4). e dierent kinds of saddle cells are prevailing among the samples of this
tribe. e original small silica cells, mainly trapezoid, have been revealed at Leymus
racemosus (Fig. 3K), whereas the close species of Leymus secalinus had more various
phytoliths, the rods and prickles to be among them (Fig. 3L).
Polypogon monspeliensis (Figs 3I, 4), Bromus squarrosus (Figs 3J, 4) and Melica
transsilvanica (Fig. 3H) belonging, accordingly, to tribes Aveneae Dumort., Bro-
meae Dumort., and Meliceae Endl., have quite similar phytoliths, but among the last
samples they are less similar in size.
Conclusion
is research has revealed the signicant morphological diversity of phytoliths,
and has also conrmed as a whole their taxonomic description, oered by Piperno
(2006) at the level of subfamilies. Among the samples of subfamily Panicoideae, the
bilobate and quadra-lobate silica cells are prevailing; the phytoliths of subfamily
Pooideae are mainly roundel and trapezoid; trapezoid and saddle phytoliths are the
most common among subfamily Chloridoideae. Subfamily Danthonioideae mainly
has elongated silica cells with wavy walls. Bilobate, as well as roundel and square,
phytoliths are characteristic for subfamily Aristidaideae. e elongated cells with
smooth walls, which are common among the mesomorphic plants of meadows and
forests (Olonova and Mezina 2011), were almost never found in investigated sam-
ples of arid and semiarid grasses of Xinjiang. Despite some deviations – some spe-
cies of tribe Stipeae Dumort. (subfamily Pooideae) have proved to be quite similar in
the shape of its silica cells to subfamily Chloridoideae. e phytoliths of Сleistogenes
squarrosa (subfamily Chloridoideae) were represented mainly by various kinds of
bilobate cells, instead of being mainly saddle.
Acquired data can be used for identication of phytoliths from sediments, but,
since all other parts of grasses contain phytoliths, like leaf blades, they should also
be investigated.

358Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
Acknowledgements
Authors are grateful to the members of Department of Soil Science in Tomsk State
University for the opportunity of burning the samples in mue, and for good ad-
vices; to Prof. Yanming Zhang and Dr. S. Duan (Xinjiang Institute of Ecology and
Geography CAS) for the organization of eld trips; to Dr. S. Eksanbekar (India) for
their useful advices and consultations on extracting of phytoliths and interpreta-
tions of obtained data. e study was supported by Chinese Academy of Sciences
(grant № 2010 T 1Z 25), Russian Fund of Basic Research (grant № 19-04-00973),
Grant of President RF № МК-88.2020.4, Grant of Russian Science Foundation №
21-74-00064.
References
Blinnikov MS (2005) Phytoliths in plants and soils of the interior Pacic North-
west, USA. Review of Paleobotany and Palynology 135: 71–98. https://doi.
org/10.1016/j.revpalbo.2005.02.006
Contreras S, Zucol AF, Méndez C, Zurita A (2019) Phytolith analysis in
Pliocene-Pleistocene uvial sediments from northeastern Argentina. Jour-
nal of South American Earth Sciences 90: 296–313. https://doi.org/10.1016/j.
jsames.2018.12.023
Danu M, Messager E, Carozza J-M, Carozza L, Bouby L, Philibert S, Anderson P,
Burens-Carozza A, Micu C (2018) Phytolith evidence of cereal processing in the
Danube Delta during the Chalcolithic period. Quaternary International, Else-
vier 504: 128-138. https://doi.org/10.1016/j.quaint.2018.03.033
Delhon C (2008) Potentiel de l’analyse des phytolithes contenus dans les pâtes
céramiques et les matériaux de construction. Cahier des thèmes transversaux
ArScAn 7: 86–93. https://halshs.archives-ouvertes.fr/halshs-00311640
Elbaum R, Weiner S, Albert RM, Elbaum M (2003) Detection of burning of plant
materials in the archaeological record by changes in the refractive indices of
siliceous phytoliths. Journal of Archaeological Science 30(2): 217–226. https://
doi.org/10.1006/jasc.2002.0828
ESRI (2012) ArcGIS Desktop and Spatial Analyst Extension: Release 10.1. Environ-
mental Systems Research Institute, Redlands, CA.
Fisher R, Bourn CN, Fisher WF (1995) Opal phytoliths as an indicator of the
oristics of prehistoric grasslands. Geoderma 68(4): 243–255. https://doi.
org/10.1016/0016-7061(95)00044-9
Golyeva АА (1996) An experience in using phytoliths analysis in soil science. Eura-
sian soil science 12: 1498–1503.
Hou XY (1988) Physical ecoregion of China and mega-agricultural development.
Bulletin of Chinese Academy of Sciences 1: 28–37; 2: 137–152.

Phytoliths from grasses in arid lands of Xinjiang, China 359
Krishnan S, Samson NP, Ravichandran P, Narasimhan D, Dayanandan P (2000) Phy-
toliths of Indian grasses and their potential use in identication. Botanical Jour-
nal of Linnean Society 132: 241–252. https://doi.org/10.1111/j.1095-8339.2000.
tb01529.x
Kurmann M (1985) An opal phytolith and palynomorph study of extant and fos-
sil soils in Kansas (U.S.A.). Paleogeography, Paleoclimatology, Paleoecology 49
(3–4): 217–235. https://doi.org/10.1016/0031-0182(85)90055-0
Liu BJ, Li CX, Ye Z (1995) Phytoliths and its paleoenvironmental signicance in the
studies of the late Quaternary Paleosols in the Yangtze delta area. Marine geol-
ogy and Quaternary Geology 15(2): 389–396.
Lo C-F (1957) e project of physic-geographical subdivision of China. In: Murza-
yev EM (Ed.) Physic-geographical subdivision of China. Izdatelstvo Inostran-
noy Literatury, Moscow, 11–44. [in Russian]
Lu H, Jia J, Wang W, Wang Y, Liao TB (2002) On the meaning of phytoliths and
its classication in Gramineae. Acta Micropaleontologica Sinica 19: 389–396.
https://www.researchgate.net/publication/290488211
Lu H, Liu K (2003a) Phytoliths of common grasses in the coastal environments of
southeastern USA. Estuarine, Coastal and Shelf Science 58 (3): 587–600. https://
doi.org/10.1016/S0272-7714(03)00137-9
Lu H, Liu K (2003b) Morphological variations of lobate phytoliths from grasses in
China and the south-eastern United States. Diversity and distributions 9 (1):
73–87. https://doi.org/10.1046/j.1472-4642.2003.00166.x
Lu H, Wang Y, Wang G, Yang H, Li Z (2000) Analysis of carbon isotope in phy-
toliths from C3 and C4 plants and modern soils. Chinese Science Bulletin 45:
1804–1808. https://doi.org/10.1007/BF02886272
Lu H, Wu NQ, Yang XD, Jiang H, Liu K-B, Liu T-Sh (2006) Phytoliths as quantita-
tive indicators of the reconstruction of past environmental conditions in China
I: phytolith-based transfer functions. Quaternary Science Reviews 25 (9–10):
945–959. https://doi.org/10.1016/j.quascirev.2005.07.014
Madella M, Alexandre A, Ball T (2005) International code for phytolith nomen-
clature 1.0. Annals of Botany 96: 253–260. https://doi.org/10.1093/aob/mci172
Metcalfe CR (1960) Anatomy of the Monocotyledons.Vol I. Gramineae. Oxford:
Clarendon Press, 731.
Murzayev EM (1966) Nature of Xinjiang and a forming of deserts of Central Asia.
Nauka, Moscow, 382. [In Russian]
Myrlyan N, Medyanik S (2008) Use of phytoliths for paleo reconstructions: identi-
cation, methods of chemical processing, and morphological diversity. Buletinul
Institutului de Geologie şi Seismologie al AŞM 2: 39–47. https://igs.asm.md/
sites/default/les/39_0.pdf [in Russian]
Neto S, dos Santos JJS, Pereira MG, Maranhão DDC, Barros FC, dos Anjos LHC
(2018) Paleoenvironmental Characterization of a High-Mountain Environment
in the Atlantic Forest in Southeastern Brazil. Revista Brasileira de Ciência do
Solo 42: e0170415. https://doi.org/10.1590/18069657rbcs20170415

360Marina V. Olonova et al. / Acta Biologica Sibirica 7: 345–361 (2021)
Ni J (2001) A Biome classication of China based on plant functional types and
the BIOME3 model. Folia Geobotanica 36: 113–129. https://doi.org/10.1007/
BF02803157
Olonova M, Barkworth M, Gudkova P (2016) Lemma micromorphology and the
systematics of Siberian species of Stipa. Nordic Journal of Botany 34(3): 322–
334. https://doi.org/10.1111/njb.00881
Olonova МV, Mezina NS (2011) Phytoliths of some mesomorphic species of blue-
grasses (Poa L.) section Stenopoa and possibility of their use in systematics.
Bulletin of Tomsk State University. Biology 1 (13): 51–60. http://journals.tsu.
ru/biology/en/&journal_page=archive&id=753&article_id=15951 [In Russian]
Patterer NI, González CA, Passeggi E, Zucol A (2013) Phytolith analysis in uvial
deposits of ambiences of the middle reach Parana river (Entre Rios, Argentina).
Boletín de la Sociedad Argentina de Botánica 48(1): 91–102. https://www.re-
searchgate.net/publication/288712221
Piperno DR (1988) Phytoliths analysis: an archeological and geological perspective.
Academic Press, San Diego, 280.
Piperno DR (2006) Phytoliths: a comprehensive guide for archaeologists and pale-
oecologists. AltaMira Press, Lanham, Maryland, 89–102.
Powers-Jones AH, Padmore J (1993) e use of quantitative methods and statistical
analyses in the study of opal phytoliths. In: Pearsall DM, Piperno DR (Eds) Cur-
rent research in phytolith analysis: applications in Archaeology and Palaeoecol-
ogy, MASCA Research Papers in Science and Archaeology. Vol. 10. University
of Pennsylvania, Philadelphia, 47–56.
Rosen AM (2008) Phytolith analysis. In: Pearsall DM (Ed) Encyclopedia of Archae-
ology. Academic Press, New York, 1818–1822. https://doi.org/10.1016/B978-
012373962-9.00247-8
Stromberg CAE (2004) Using phytolith assemblages to reconstruct the origin and
spread of grass-dominated habitats in the great plains of North America during
the late Eocene to early Miocene. Palaeogeography, Palaeoclimatology, Palae-
oecology 207 (3–4): 239–275. https://doi.org/10.1016/j.palaeo.2003.09.028
Twiss PC (1987) Grass – opal phytoliths as climatic indicators of the Great plains
Pleistocene. In: Johnson WC (Ed) Quaternary Environments of Kansas. Kansas:
Lawrence, 179–188. http://www.kgs.ku.edu/Publications/Bulletins/GB5/gb5.
pdf
Wang C, Lu H, Gu W, Wu N, Zuo X, Li F, Wang D, Dong Y, Wang S, Liu Y, Bao Y,
Hu Y (2018) e development of Yangshao agriculture and its interaction with
social dynamics in the middle Yellow River region, China. e Holocene 29 (1):
233–245. https://doi.org/10.1177/0959683618804640
Witty JE, Knox EG (1964) Grass opal in some сhestnut and forest soils in north
central Oregon. Soil Science Society of America proceedings 28 (5): 685–687.
https://doi.org/10.2136/sssaj1964.03615995002800050030x

Phytoliths from grasses in arid lands of Xinjiang, China 361
Wu N, Lu H, Nie G, Wang Y, Yi M, Gu G (1992) e study of phytoliths in C3
and C4 grasses and its paleoecological signicance. Quaternary Sciences 8 (3):
241–151.
Zhan B-C, Duan Yu-W, Qiao L (1957) e project of climatic subdivision of China.
In: Murzayev EM (Eds) Physic-geographical subdivision of China. Izdatelstvo
Inostrannoy Literatury, Moscow, 70–130. [In Russian]