Bulbophyllum guamense (Siboyan halom tano; Siboyas halumtano) is an epiphytic orchid (family Orchidaceae) characterized by leaf-bearing pseudobulbs that are spaced or clustered on a creeping or mat-like formation of fiber-covered rhizomes or “stems.” The pseudobulbs are pear-shaped to almost round, smooth during the rainy season and ribbed during the dryer months. Single oblong-elliptic leaves, 10 to 15 cm (4 to 6 in) long and 2.5 to 3.8 cm (1 to 1.5 in) wide, are fleshy, stiff, and emerge from the top of the pseudobulbs. The inflorescence is longer than the leaves. Single flowers are fleshy and greenish-yellow with a faint, carrion-like scent. Fruits are a capsule about 5 x 1 cm (2 x 0.4 in) with dust-like seeds.