# Morphological, Anatomical, and Phytochemical Studies of _[PERSON]_ [PERSON]. [PERSON]
## 1 Introduction  
Seeds of many plant species are a valuable source of various nutrients, e.g., oil, protein, carbohydrates, and biologically active secondary metabolites. Seed oils are rich in unsaturated fatty acids [1], which are highly important for human health, as they prevent the development of many diseases such as cancer, cardiovascular diseases, and diabetes. They are also essential for the proper development of the fetus and cognitive functions [2]. Tools (tocopherol and tocotrienols) present inoils, referred to as vitamin E, play important roles in the human organism, preventing oxidation of the components of the cell membrane, polyunsaturated fatty acids, and low-density lipoproteins [3]. Additionally, seeds have a diversified mineral composition with high content of various micro- and macroelements [4]. Plant seeds are, therefore, a valuable source of phytochemicals with great medicinal and dietary importance. They are also important in animal nutrition. Moreover, seed oils are a desirable component of various cosmetic preparations [5; 6]. This prompts research on plant seeds that have not been studied so far.  
_Carlina acaulis_ L. (Figure 1A) is a monocarpic perennial plant from the Asteraceae family occurring in South and Central Europe. _Carlina_ root has been used in medicine since ancient times mainly for treatment of skin diseases, in treatment of dental and gastrointestinal tract diseases, and as an anthelmintic and diuretic agent. Some reports also indicate the therapeutic potential of aerial parts in skin diseases [7; 8]. The chemical composition of the roots and green parts of _C. acaulis_ is quite well known and established mostly by chromatographic techniques: high-performance thin-layer chromatography (HPTLC), high-performance liquid chromatography (HPLC), and gas chromatography (GC). For example, carlina oxide and inulin were found as the main phytochemicals in roots [9], and leaves were shown to contain flavonoids [10], chlorogenic acids, and considerable amounts of oleanolic and unsolic acids [11; 12]. In contrast, there are scarce reports on the phytochemistry of seeds. They are limited to one publication from 1969 [13], in which the fatty acid profile of _C. acaulis_ fruit oil was examined and only five fatty acids were identified and quantified.  
The seeds of Asteraceae plants are botanically their fruits and are referred to as cypselae. The cypsela is a complex, indehiscent, dry, unilocular fruit with a single seed not adhere to the pericarp and derived from an inferior ovary [14]. The data in the literature indicate that cypselae of some Asteraceae species are rich in protein and oil (e.g., [15]), and immature cypselae of some genera (_Taraxacum_, _Hieracum_, _Pilosella_) contain large amounts of polysaccharides [16; 17; 18].  
The aim of our study was to investigate the morphological and anatomical structure of _C. acaulis_ cypselae using such imaging techniques as light and scanning electron microscopy (SEM). Moreover, the chemical composition of cypselae was evaluated taking into account the content of primary and secondary metabolites as well as the mineral profile. The following techniques have been used: gas chromatography with mass spectrometry (GC-MS), HPLC with photodiode (DAD) and fluorescence (FLD) detection, ultra-performance liquid chromatography with fluorescence detection (UPLC-FLD), inductively coupled plasma-optical emission spectrometry (ICP-OES), attenuated total reflectance infrared spectroscopy (ATR-IR), and UV-VIS spectrophotometry. To our knowledge, this is the first study on the cell structure and chemical composition of the _C. acaulis_ cypsela.  
Figure 1: (**A**). Flowering plant _Carlina acaulis_ L., (**B**). Mature cypselae.