Judul: Characterization Morphology, Agronomy, and  Phylogenetic Relationships of Scindapsus sp. from West Kalimantan
Abstrak: Scindapsus sp. merupakan tanaman hias daun yang 30 dari 60 spesiesnya berada di Indonesia, namun sebagian besar belum teridentifikasi. Penelitian ini bertujuan mengidentifikasi karakter morfologi daun, mempelajari pertumbuhan dan perkembangan tanaman, serta menganalisis hubungan kekerabatan beberapa jenis Scindapsus sp. asal Hutan Kapuas Hulu, Kalimantan Barat. Penelitian dilakukan pada bulan Mei hingga November 2022, dengan tiga tahap pengamatan, yaitu pengamatan morfologi dan pertumbuhan di greenhouse, pengamatan histologi daun di laboratorium, dan pengamatan pasca perbanyakan. Penelitian dilakukan pada tiga jenis Scindapsus, yakni Scindapsus sp. 1 (S. pictus ‘Platinum’), Scindapsus sp. 2 (S. pictus ‘Hassk’), dan Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’). Hasil penelitian menunjukkan karakter morfologi, anatomi, dan pertumbuhan pada setiap jenis Scindapsus. Scindapsus sp. 1 (S. pictus ‘Platinum’) memiliki keragaan yang besar. Karakter warna dan corak daun menjadi ciri pembeda utama antar jenis. Ukuran palisade dan stomata selaras dengan pertumbuhan tanaman. Hubungan kekerabatan ketiga jenis scindapsus ditunjukkan oleh hasil bagan dendrogram berdasarkan beberapa parameter. Dendrogram Scindapsus sp. dengan kekerabatan paling dekat berdasarkan karakter warna dan corak daun, warna batang, kerapatan stomata serta rasio palisade daun adalah Scindapsus sp. 1 (S. pictus ‘Platinum’) dan Scindapsus sp. 2 (S. pictus ‘Hassk’), sedangkan berdasarkan karakter pertumbuhan tanaman yaitu pertambahan ruas dan daun, ukuran batang, ruas, dan daun menunjukkan Scindapsus sp. 2 (S. pictus ‘Hassk’) lebih dekat dengan Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’)., Scindapsus sp. is a tropical foliage plant from the Araceae family, consisting of 60 species, 30 of which are found in Indonesia. However, most of these species have not been fully identified in terms of morphology and growth. The aim of this research is to identify leaf morphological characteristics, study plant growth and development, and analyze the phylogenetic relationships of several species of Scindapsus sp. from the Kapuas Hulu forest in West Kalimantan. The research was conducted from May to November 2022 and included three stages: morphological and growth observations in the greenhouse, histological observations in the laboratory, and post-propagation observations. The study focused on three cultivars of Scindapsus, namely Scindapsus sp. 1 (S. pictus ‘Platinum’), Scindapsus sp. 2 (S. pictus ‘Hassk’), and Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’). The results showed the morphology and growth characteristics of each type of Scindapsus. The plant Scindapsus sp. 1 (S. pictus ‘Platinum’) had the largest size compared to the other cultivars. The color and pattern of the leaves were the main distinguishing features between the cultivars. The sizes of the palisade cells and stomata were compatible with the growth of the plants. The phylogenetic relationships between the cultivars were illustrated by a dendrogram chart based on several parameters. The dendrogram of Scindapsus sp. based on leaf color and pattern, stem color, stomata density, and palisade leaf ratio shows that Scindapsus sp. 1 (S. pictus ‘Platinum’) and Scindapsus sp. 2 (S. pictus ‘Hassk’) are most closely related. However, based on plant growth characteristics such as node and leaf increment, stem size, node length, and leaf size, Scindapsus sp. 2 (S. pictus ‘Hassk’) is closer to Scindapsus sp. 3 (S. argyraeus ‘Black Exotica’).
Keyword: characterization, histology, morphology, dendrogram, scindapsus

Judul: Keanekaragaman Morfologi Sisik Tumbuhan Paku Terestrial di Kampus Institut Pertanian Bogor, Dramaga
Abstrak: Kampus IPB Dramaga memiliki keanekaragaman hayati yang tinggi, salah satunya ialah tumbuhan paku terestrial. Kelimpahan ini berkaitan dengan tingkat kelembapan yang tinggi dan intensitas cahaya yang rendah. Tumbuhan paku memiliki sisik atau rambut berupa indumentum yang menutupi bagian rimpang, tangkai daun serta bagian muda helaian daun. Morfologi sisik dapat digunakan dalam identifikasi jenis tumbuhan paku. Penelitian ini bertujuan mengetahui keanekaragaman morfologi sisik tumbuhan paku terestrial yang dikoleksi dari lingkungan kampus IPB Dramaga. Bagian sisik paku diamati morfologinya di bawah mikroskop cahaya yang disambungkan dengan indomicro dan dihitung kerapatannya. Hasil pengamatan morfologi sisik pada 20 jenis tumbuhan paku dari 3 suku dijumpai sisik rimpang dan sisik tangkai daun berbentuk lanset, garis, bundar telur, mendabus, dan mengginjal. Bagian ujung sisik beragam mulai dari ujung menebal, tipis, dan seperti jarum. Selain itu, bagian tepi sisik bervariasi yaitu rata, berbenang, atau berseta. Penempelan pangkal sisik yang dijumpai yaitu basifix, pseudopeltate, dan peltate. Warna sisik bervariasi mulai dari putih, kuning, cokelat kekuningan, cokelat muda, dan cokelat tua. Sisik yang diamati memiliki satu sampai dua lapis sel. Kerapatan sisik yang dihitung berkisar dari 0,6 sampai 21,3/mm2. Suku Pteridaceae memiliki persamaan ciri lebih banyak antar marganya dibandingkan dengan kedua suku lainnya, namun persamaan ciri ini tidak dapat digunakan untuk identifikasi dan klasifikasi taksonomi, karena tidak ciri spesifik dari setiap marga. Kata kunci: indumentum, peltate, rimpang, sisik, tangkai daun, IPB Dramaga Campus has high biodiversity, one of which is terrestrial ferns. This abundance is related to high humidity levels, and low light intensity. Ferns have scales or hairs in the form of an indumentum that covers the rhizome, petiole, and young part of the leaf blade. The morphology of scales can be used in the identification of fern species. This study aims to determine the morphological diversity of terrestrial fern scales collected from the IPB Dramaga campus. The morphology of the nail scales was observed under a light microscope connected to an indomicro and the density was calculated. The results of morphological observations of scales on 20 species of ferns from 3 families found rhizome scales and petiole scales in the form of lanceolate, linear, ovate, subulate, and reniform. The tip of the scales varies from thick, thin, and needle-like. In addition, the edges of the scales vary, namely flat, threaded, or banded. The attachments of the base of the scales found were basifix, pseudopeltate, and peltate. The color of the scales varies from white, yellow, fawn, light brown, and dark brown. The scales observed have one to two layers of cells. The calculated scale density ranged from 0.6 to 21.3/mm2 Pteridaceae have more common characteristics between their genera than the other two families, but these similarities cannot be used for taxonomic identification and classification, because there are no specific characteristics of each genus. Keywords: indumentum, peltate, petiole, rhizome, scale
Keyword: indumentum, peltate, petiole, rhizome, scale

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
Keyword: