<![CDATA[ABSTRAK Porang (Amorphopllus muelleri Blume) merupakan anggota famili Araceae, mengandung kristal kalsium oksalat (CaOx , dan memiliki beberapa periode tumbuh. Periode tumbuh berbeda diduga berpengaruh terhadap kerapatan kristal CaOx. Penelitian ini bertujuan untuk mengetahui pengaruh periode tumbuh dan bagian umbi berbeda (tepi dan tengah) terhadap kerapatan kristal CaOx, kristal rafida, dan kristal druse. Sampel umbi diperoleh dari Madiun sebanyak tiga umbi. Masing-masing umbi berfungsi sebagai ulangan. Dari masing-masing umbi dibuat irisan setipis mungkin di bagian tepi dan tengah masing-masing sebanyak 3 keping dan dijernihkan menggunakan metode Ilarsan yang telah dimodifikasi. Irisan yang sudah jernih dibuat preparat dan diamati di bawah mikroskop pada perbesaran 100X. Data yang diperoleh dianalisis dengan menggunakan SPSS 16 for windows. Hasil penelitian menunjukkan bahwa periode tumbuh tidak berpengaruh nyata terhadap kerapatan kristal CaOx dan jenis kristal druse dan rafida. Sebaliknya, bagian umbi berpengaruh nyata terhadap kerapatan kristal CaOx dan jenis kristal druse dan rafida. Umbi bagian tengah menghasilkan kerapatan kristal lebih tinggi dibandingkan tepi. Kata kunci : kristal CaOx, Periode tumbuh, Porang (A. muelleri Blume). ABSTRAC A. muelleri Blume is a member of family Araceae,contains calcium oxalate crystals, andhassome growth period. Different of growth period was proposed to influence density of CaOx crystals. The aim of this research wasto know density of calcium oxalate crystals under different growth period and tuber part (edge and center). The three-tuber sample were obtained from Madiun. Each tuber has function as replicate. From edge and center part of each tuber was sliced as thin as possible at least three slicesand cleared according to Ilarsan modified method. The cleared slice was processed as slide for microscopy observation. Counting density of crystal were conducted under microscope with 100x magnification.The obtained data were analyzed using SPSS 16 for windows. The result showed that growth period was not significantly influence density of crystal and druse and raphid crystals. The part of tuber, however, was significantly influence density of crystal and druse and raphid crystals which center tuber gave higher density than edge part of tuber. Key word : A. muelleri Blume, calcium oxalate crystals, growth period.]]>
