Nolina is a genus of tropical xerophytic flowering plants belonging to the Asparagaceae plant family. The native distribution of the genus includes most of Mexico and the southern regions of the United States. Especially in the USA, members of the genus are known as beargrasses, some of which are cultivated as ornamental plants. Nolina species grow large rosettes of many leaves, with many species forming large, erect trunks, with some species branching to contain multiple rosettes of leaves. They are typically large plants, and are dioecious, with male and female flowers being produced on different plants. The genus is named for 18th century French arboriculturist Abbé C. P. Nolin.

Classification

In the APG III classification system of plant taxonomy, Nolina is a member of the Asparagaceae family of plants, and within this family, Nolina is part of a subfamily, the Nolinoideae. In the past, many members of the Nolinoideae, including Nolina, were placed in the now defunct Ruscaceae family). Former alternative placements include Nolinaceae and Agavaceae. Previously, some botanists have included the genus Beaucarnea in Nolina, and over time, multiple species of both genera have been moved back and forth between the two genera. More recent molecular phylogenetic research found that Beaucarnea and Nolina are well supported by DNA and morphological evidence as being two distinct genera.

Description

Nolina are perennial plants, with some growing as tufts of leaves arising from near ground level with little or only a short above ground stem, whilst others grow in a tree-like manner forming a woody, leafless caudex or trunk of up to about 2-3m, that with age, may branch to form multiple branches. The shorter species, especially those not forming an above ground stem, usually form colonies, often with many rosettes. The leaves are arranged into rosettes of many long, linear leaves, with the leaves being broader where they meet the stem. The inflorescence consists of a scape (or a bare stem arising from the leaf rosettes) of between 5-250cm length, with panicles of flowers, of 30 to 180cm in length, held along the scape. Each node holds 2-5 functionally unisexual flowers. The tepals are white, cream or light tan. The fruits are capsular, 3-locular, 3-lobed and often inflated.

Species

As of November 2024, World Flora Online (WFO) lists the genus Nolina to contain 30 accepted species, with Plants of the World Online (POWO) recognising 35 accepted species. As of November 2024, the 35 accepted species of Nolina accepted by Kew/POWO are as follows: As of November 2024, the five species recognised by POWO not currently accepted by WFO are:

Formerly placed here