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,
Justicia (plant) leaves which are often strongly veined; but they are primarily cultivated for their showy tubular flowers in shades of white, cream, yellow, orange or pink. They are not hardy below , so may be grown under glass in frost-prone areas. "Justicia americana" (American water-willow), is native to eastern North America north to southern Ontario; it is the hardiest species in the genus, hardy to USDA Plant Zone 4. "Justicia ovata" (looseflower water-willow) occurs nearly as far north, reaching Michigan. "Justicia brandegeeana" (formerly "Beloperone guttata", commonly called shrimp plant) is native to Mexico. It is hardy to −4 °C but will