Floral morphology and chromosome characteristics of bamboo orchid from Menoreh Hills, Kulonprogo

Purpose: One of the most common orchids in Menoreh Hills, Kulonprogo is bamboo orchids (Arundina). This genus has only one species but has a wide variety of flower phenotypic that spreads around the world. The aims of this research were to characterize the flower morphology and chromosome content of bamboo orchids from Menoreh, related to their taxonomic status. Research Method: Observation of morphological characters was carried out to assist the identification process of the bamboo orchid species. The squashing method is used in the preparation of bamboo orchid chromosomes. The results were analyzed with Image Raster 3.0, Corel Draw 11 and Ms. Excel 2010. Findings: Bamboo orchid from Menoreh, Kulonprogo is a flower with white sepals and petals, the tips of sepals are yellowish brown. Labellum is white, with a thin purple stripe on the edges, and the base is yellow. Chromosomes number 2n = 20, with the formula karyotype 2n = 2x = 20 = 16m + 4sm. Chromosomes' absolute length is 0.55-1.64 mu m and relative lengths 0.57-1.615 mu m. Based on morphological characters, Menoreh's bamboo orchid has similarities with A. graminifolia, whereas based on chromosomes number and karyotype formula, it is different. Limitations: There are bamboo orchids with a wide variety of flowers around world. However, the sample collection is only limited to bamboo orchid in Purwosari village, Kulonprogo. Value: Menoreh's bamboo orchid has a potential to be a new variant from the A. graminifolia population, based on the differences in morphological and chromosomal characters.