In general, all plants except liverworts have stomata in their sporophyte stage. The clade consisting of the plants plus their closest relatives, the charophytes . The narrow stalk of the pistil , located above the ovary but below the stigma . A cluster of sporangia which have become fused in development. When the sepals and petals of a flower are indistinguishable, they are referred to as tepals.
Tepals are common in many groups of monocots .
Plants which have no roots, stems, or leaves are called thalloid, such as liverworts and hornworts . Any tall plant, including many conifers and flowering plants , as well as extinct lycophytes and sphenophytes. An underground stem which has been modified for storage of nutrients, such as a potato. Force exerted outward on a cell wall by the water contained in the cell. This force gives the plant rigidity, and may help to keep it erect.