''Cycas calcicola'' is a species of

cycad Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants o ...

in the genus ''

Cycas ''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity in ...

'', native to northern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

in the northwest of

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

. The stems are erect, 2–5 m tall and 16–22 cm diameter. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are variably deep green and glabrous to white tomentose above, and persistently white tomentose below, 60–130 cm long, pinnate, with 210-410 leaflets. The leaflets are 5–12 cm long and 2–4 mm wide, and lie flat either side of the leaf stem (not in a 'v'-shape like most other ''Cycas'' species). The petioles are 18–30 cm long, and armed with sharp spines at the base. The female

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

are open, with

sporophyll A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or mi ...

s 12–18 cm long, with four to six ovules per sporophyll. The lamina is lanceolate, with spined dentate margins and an apical spine. The

sarcotesta The sarcotesta is a fleshy seedcoat, a type of testa. Examples of seeds with a sarcotesta are pomegranate and some cycad seeds. The sarcotesta of pomegranate seeds consists of epidermal cells derived from the integument In biology, an integu ...

is orange-brown, the sclerotesta short ovoid to globular, with a network of shallow grooves. The male cones are solitary, narrow ovoid, 25–30 cm long and 5–7 cm diameter, brown, the sporophylls 25–30 mm long with an upturned apical spine.

Habitat

This cycad grows in a hot, dry, climate, often in association with ''

Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...

'' and ''

Livistona ''Livistona'' is a genus of palms, the botanical family Arecaceae, native to southeastern and eastern Asia, Australasia, and the Horn of Africa. They are fan palms, the leaves with an armed petiole terminating in a rounded, costapalmate f ...

''. It was first found on

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

soil, from which the name ''calcicola'' "lime-dwelling" derives, but is not confined to limestone, also occurring on soils derived from

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

and

schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes o ...

References

Cycad Pages: ''Cycas calcicola''

IUCN Redlist: ''Cycas calcicola''
*Whitelock, L. M. (2002). The Cycads. Timber Press, Portland, Oregon. {{Taxonbar, from=Q5197924

calcicola ''Calcicola'' is a genus in the Malpighiaceae, a family of about 75 genera of flowering plants in the order Malpighiales. ''Calcicola'' comprises 2 species of shrubs or treelets native to Mexico Mexico (Spanish: México), officially the Un ...

Flora of the Northern Territory Cycadophyta of Australia Endemic flora of Australia Least concern flora of Australia