a comparative study of stucco design and plants motifs in ctesiphon palace and early iranian mosques (mosque of naien, mosque of ardestan, mosque of isfahan)

decorative arts have got a special place in iranian architecture traditionally. these types of arts are the symbol of nation's ethnics and indigenous features and also express the artist's feelings of those times. stucco is one type of the decorative arts that has decorated many buildings -especially palaces-that belong to the pre-islamic period and also mosques that built in the islamic era. plant patterns can be considered as one of the remarkable pattern in stucco art. in pre-islamic time, various examples of those patterns have been seen in ctesiphon palace in sassanid persian empire. the purpose of this paper is study and recognition of plant motifs in stucco of the sassanian palace (palace of ctesiphon) and reform of them in three historical mosques in early islamic period in iran. in other words, by the use of descriptive and analytical method, this research explains and classifies plant motifs in stuccoes remained from sassanian period, and then compares it with the ones in three mosques(mosque of nain, mosque of ardestan and mosque of isfahan) in islamic architecture of persia. plant motifs in stuccoes of sassanian palaces, are abstracted from nature and have gotten different forms that are as follows: palmetto motifs, vines and ivies, lotus flower, grape and pomegranate, the lotus flower and rosette, oak-like motif, leaves of fig and motifs like stylized leaves; such as figs, palms, artichokes and lotus leaves. by the emergence of islam in iran, religious believes affected the art and artistic trends. duo to the prevention of using human and animal figurers in stucco design; these motifs altered and became more complicated. plant motifs in sassanid time faced some changes and then were represented as arabesque in islamic period. its unique examples can be found in the mosques of this period. most popular islamic arabesques are rhythmic linear patterns of scrolling stems that end at a form like trunk of an elephant or open mouth of torpedoes. besides them, vine leaves and grape clusters, acanthus leaves, flower leaves, pot plants, rounded leaves, palm leaves; pine, pear and pomegranate are other forms of arabesque. in most of the cases, islamic arabesque are found in combination with plant motifs from sassanid era. in nain mosque, besides the use of  palmetto and acanthus motifs from sassanid era, the grape motifs had appeared in different way. the woven grape motifs have covered parts of the columns and sanctuary. the use of some different forms of plant motifs in this mosque can be partly an experimental practice. in ardestan mosque, the emergence of the initial islamic arabesques can be seen. these motifs have not been  fully abstracted yet and its combinations are reminder of famous carvings in taq-e bostan. also, the frieze on the entrance ivan of the mosque is a combination of manuscript and arabesque. in isfahan mosque, arabesque motifs evolved and different types of arabesques emerged; especially in the sanctuary of the oljeitu. moreover, in many cases quranic verses are seen in combination of arabesque.