Plant morphology share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany. Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive structures. The vegetative structures of vascular plants includes the study of the shoot system, composed of stems and leaves, as well as the root system. The reproductive structures are more varied, and are usually specific to a particular group of plants, such as flowers and seeds, fern sori,
Trigonidium (plant) Trigonidium (plant) Trigonidium, abbreviated as Trgdm in horticultural trade, is a genus of orchids comprising roughly twenty species found from Mexico to Brazil. "Trigonidium" derives from the Greek "trigonon", meaning "triangle", in reference to the triangular shape of the flowers. The epiphytes and lithophytes of the genus have long or short rhizomes. Its pseudobulbs are cylindrical or ovoid with overlapping sheathes at their base and one or two leaves at their apex. The inflorescences of the genus are basal, erect, and single flowered, with the flower usually as long or longer than the leaves. The flowers are tubular at the