genus yucca: tropical American plants with stiff lancelike leaves and spikes of white blossoms; sometimes considered a genus of Amaryllidaceae
liliid monocot genus: genus of monocotyledonous plants comprising mostly herbs having usually petaloid sepals and petals and compound pistils
major lobe: the maximum lobe in the radiation pattern which is intended to be along the forward axis and which gives the effect of a beam