''Spinifex sericeus'', commonly known as hairy spinifex, rolling spinifex, beach spinifex or coastal spinifex, is a

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in law ...

. It is native to Australia,

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

, New Caledonia, and

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

. It is an important

pioneer species Pioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire. Pioneer flora Some lichens grow on rocks without soil, ...

which colonises coastal

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...

s, binding loose sand with its horizontal runners. The 1889 book ''The Useful Native Plants of Australia'' records that common names included "Spring Rolling Grass" and that it "has no claim whatever as a food plant for stock, and can only be recommended as a sand-binder in fixing drift sands when encroaching on valuable land. For this purpose it deserves more attention than has hitherto been bestowed upon it. It is a plant of comparatively rapid growth, and would give effectual aid in checking the inroads of wind-driven sand, conditionally that the plants be carefully conserved from fire."

Description

''Spinifex sericeus'' has branched

stolon In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external ...

s and rhizomes extending up to . The leaves have a

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many Poaceae, grasses (Poaceae) and Cyperaceae, sedges. A ligule is also a strap-shaped extension of the corolla ...

of a rim of dense hairs; the blades are flat and densely silky. The male

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

is an orange-brown terminal cluster of spiky

raceme A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the sh ...

s subtended by silky bracts. The female inflorescence detaches at maturity, a globose seed head of

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

racemes up to 20 cm in diameter which becomes a

tumbleweed A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumb ...

References

Panicoideae Grasses of New Zealand Flora of New Caledonia Flora of Tonga Poales of Australia Flora of Victoria (Australia) Flora of Queensland Flora of New South Wales Flora of Tasmania Taxa named by Robert Brown (botanist, born 1773) Dioecious plants {{Panicoideae-stub