Judul: Keanekaragaman Selaginella di Jawa Barat.
Abstrak: Selaginella is a genus of ferns in the family Selaginellaceae. It is characterized by having small leaves and the spongarium on the tip of each branch. The society of West Java have been a long time used Selaginella as vegetable and dill, but the taxonomic information of Selaginella in West Java is still poorly known. The aim of this research was to describe the diversity of Selaginella in West Java. This research used 316 herbarium specimens of Selaginella collected by Plant Taxonomy Laboratory, Department Biology of Bogor Agricultural University and Herbarium Bogoriense Botanical, Research and Development Cibinong. From each specimen was observed the mophological characters, recorded the spread site, identified, then arranged the identification key. This study showed that 18 species found in West Java, namely S. aristata, S. biformis, S. ciliaris, S. frondosa, S. intermedia, S. involvens, S. mayeri, S. opaca, S. ornata, S. plana, S. remotifolia, S. rothertii, S. subalpina, S. subspinulosa, S. uncinata, S. willdenovii, S. zollingerian and Selaginella sp 1. Selaginella is able to live at altitudes ranging from 20 m above sea level (asl) to > 2500 m asl, with a variety of habitats including primary forest, in the rice fields, near the waterways, and in the open area. An identification key of Selaginella in West Java was provided in this paper.
Keyword: identification key, Selaginella, taxonomic, West Java.

Judul: Keanekaragaman Selaginella di Jawa Tengah
Abstrak: Selaginella is a single genus belong to family Selaginelaceae which include approximately 750 species spread all over the world. The diversity of Selaginella can be found in lowland to mountain rainforest. This study aimed to describe the diversity of morphological characters and the distribution of Selaginella in Central Java, then to provide descriptions and identification key of Selaginella species in Central Java. The method used to assess the diversity Selaginella in Central Java included observation and identification of morphological characters. In Central Java, there were found 10 species of Selaginella, namely S. plana, S. remotifolia, S. involvens, S. ornata, S. ciliaris, S. opaca, S. modica, S. aristata, S. subalpina, and Selaginella sp. Selaginella varied on some morphological characteristics such as branching pattern, rhizofor, lateral leaves, median leaves, axillary leaves, and Strobilus shape. The distribution of Selaginella is fairly even in Central Java ranging from the altitude of 200 to 2771 m asl. Selaginella species found in the lowest altitude was Selaginella sp. (200 m asl), while at the highest altitude was S. plana (2771 m asl).
Keyword: Selaginella, Selaginellaceae, Taxonomy, Central Java.

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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