Lomandra, commonly known as mat rushes, is a genus of about 51–64 perennial herbaceous monocots native to Australia, belonging to the family Asparagaceae (subfamily Lomandroideae, order Asparagales). The genus was first described by the French botanist Jacques Labillardière in 1805, and is sometimes also placed in the segregate family Lomandraceae. A synonym in older literature is Xerotes.
Plants are tufted dioecious perennials — that is, male and female flowers are borne on separate individuals — forming dense clumps of long, narrow, blade-like leaves that arise directly from a central stemless base supported by thick woody rhizomes and fibrous roots. Leaves are linear or terete, with distinctive sheathing basal margins; leaf apices may be entire or toothed. Inflorescences are spike-like, raceme-like, or panicle-like; flowers are small and borne separately or in dense or open clusters. The female perianth is usually larger than the male and hardens in fruit. Seeds are globose to ellipsoidal, brown, orange, or reddish, enclosed in a globose, cylindrical, or trigonous capsule.
All species are native to Australia, where the genus occurs in every state; two species also extend into New Guinea and New Caledonia. Lomandras occupy a wide range of habitats, from banks of creeks, swamps, and wet places to rocky hillsides, cliffs, and open forests in sandy soils. Well-known members include Lomandra longifolia (longleaf mat-rush), one of the most widespread species, and Lomandra hystrix, found characteristically near watercourses. Several species are valued as hardy, drought-tolerant garden plants and in ecological restoration plantings.
Etymology
The genus name Lomandra derives from the Greek loma (border or margin) and aner/andros (man or stamen), referring to the stamens that are inserted on the margin or rim of the perianth tube — a morphological feature noted in the genus description. The genus was established by Jacques Labillardière in 1805. An older synonym, Xerotes, is also encountered in early Australian botanical literature.
Distribution
Lomandra is an almost entirely Australian endemic genus, with all ~50–64 species native to Australia and occurring in every Australian state. Two species extend beyond Australia into New Guinea and New Caledonia. Within Australia, the genus occupies a wide variety of environments — from coastal lowlands and creek banks to montane open forests and arid rocky hillsides — reflecting its broad ecological tolerance.
Ecology
Lomandra species colonise a wide spectrum of habitats, including banks of creeks, swamps, rocky hillsides, cliffs, and open eucalypt forests. They grow in sandy, loamy, and clay soils ranging from mildly acid to mildly alkaline pH, and tolerate both full sun and partial shade. Lomandra hystrix is characteristic of moist habitats near watercourses, while Lomandra longifolia thrives on creek banks as well as dry rocky slopes. The flowers of at least some species are pollinated by beetles.
Cultural Uses
Indigenous Australians have used several Lomandra species for food and material culture. The white leaf bases of Lomandra longifolia are edible raw and have a flavour likened to green peas; the flowers (particularly male flowers) are also eaten raw. The tough, flexible leaves of mat rushes were widely used by Aboriginal peoples for weaving baskets, mats, and string — a use reflected in the common name "mat rush."
Cultivation
Lomandra species, especially Lomandra longifolia and its cultivars, are widely grown as low-maintenance ornamental and restoration plants in Australian gardens. They tolerate a broad range of soils (sandy to clay) and pH levels, grow in full sun to partial shade, and are notable for their drought and frost tolerance once established. The genus is dioecious, so both male and female plants are needed for seed production. Numerous compact and variegated cultivars derived from Lomandra longifolia have become popular in landscape horticulture throughout Australia and in similar climates globally.
Taxonomy Notes
Lomandra was placed historically in several different families — Liliaceae, Xanthorrhoeaceae, and Dasypogonaceae — reflecting longstanding uncertainty about the placement of Australian monocot genera. It is now firmly placed in Asparagaceae (subfamily Lomandroideae, order Asparagales) following molecular phylogenetic analyses. Some authorities still recognise the segregate family Lomandraceae. The synonym Xerotes is recorded in APNI. Plants of the World Online recognised 64 species as of June 2024, while some counts cite ~50–51 species.
