Species profile—Croton magneticus
Classification
Plantae (plants) → Equisetopsida (land plants) → Euphorbiaceae → Croton magneticus
Sighting data
Species details
- Kingdom
- Plantae (plants)
- Class
- Equisetopsida (land plants)
- Family
- Euphorbiaceae
- Scientific name
- Croton magneticus Airy Shaw
- WildNet taxon ID
- 11493
- Nature Conservation Act 1992 (NCA) status
- Endangered
- Conservation significant
- Yes
- Confidential
- No
- Endemicity
- Native
- Pest status
- Nil
- Short Notes
- BRI 219857, status annotated by author
- Description
- Croton magneticus is a small tree or shrub growing to 5 m high and is monoecious, deciduous and perennial. The indumentum is ginger to silver. The branchlets may be rounded, with dense stellate trichomes when young, becoming glabrous with age. The stipules are subulate, 0.3 to 0.9 mm long by 0.2 mm wide, entire, with sparse to dense stellate trichomes. The leaves are alternate, petiolate, discolorous. The petioles are 5 to 25 mm long and 1 mm wide, with dense stellate trichomes. The lamina is cuneate-obovate, elliptic, elliptic-ovate, 20 to 155 mm long by 12 to 60 mm wide, penninerved with 7 to 9 lateral nerves per side of the midrib. The upper lamina surface is glabrous or with scattered stellate trichomes, matt green in colour and the venation is obscure. The lower surface is scabrid to weakly velutinous, with sparse to dense stellate trichomes, silver in colour, with weakly developed lateral veins. The lamina margins are denticulate to weakly crenate with 8 to 24 short teeth up to 2 mm long, with prominent foliar glands. The inflorescence is up to 80 mm long, but often reduced to a single flower, often unisexual but occasionally bisexual and androgynous, with a peduncle up to 10mm long. The male flowers are 3 to 5 mm long, 4.5 to 5 mm in diameter, held singly on inflorescence. The female flowers are 4 to 4.5 mm long, 3.5 to 5 mm long, also held singly. Fruits are trilobate, globose, 8 mm long and 8 mm in diameter, with dense stalked stellate trichomes. The seeds are obloid-ovoid, 5 to 5.5 mm long, 4.2 to 4.5 mm wide, 3 mm thick, pale brown in colour. The ventral seed surface is bifacial and the dorsal surface is rounded. The caruncle is crescent shaped, 1.5 to 1.7mm long by 0.7 to 1mm wide, and cream in colour (Forster, 2003).
C. magneticus is similar to C. arnhemicus, however it is easily distinguished by its penninerved leaves, as opposed to the palminerved leaves of C. arnhemicus (Forster, 2003). - Map
- View Map
- Distribution
- Croton magneticus is restricted to an area between Greenvale to near Collinsville in north-eastern Queensland. C. magneticus is noted to be rare to occasional on Gloucester island and Mt Stuart (near Townsville) and frequent to common on Magnetic Island, Mt Abbott and Mt Blackjack. This species is recorded from Magnetic Island, Gloucester Island and Dryander National Parks, and Blackjack Mountain Nature Refuge (DSEWPC, 2012; Queensland Herbarium, 2012).
- Distributional limits
- -19.1116666, 144.8367026
-21.0194445, 148.5611112 - Range derivation
- Range derived from extent of the taxon's verified records
- Habitat
- Croton magneticus grows in deciduous vine thickets (dry rainforest) on soils derived from sandstone, granite or acid agglomerate substrates, often in association with Croton arnhemicus and C. phebalioides (Forster, 2003; Queensland Herbarium, 2012).
- Reproduction
- Croton magneticus flowers from December to February following storm or seasonal rains, fruiting occurs from January to March. Dormant buds are held on the plants for much of the year (Queensland Herbarium, 2012; Forster, 2003).
- Threatening processes
- The main identified threat to Croton magneticus in the past has been the destruction of habitat by clearing (Forster, 2003).
The main potential threats to C. magneticus include inappropriate fire regimes, and the invasion of species habitat by exotic weeds such as Lantana (Lantana camara) and Rubber Vine (Cryptostegia grandiflora). The proliferation of Lantana also alters the fuel characteristics and flammability of the relatively fire-sensitive deciduous vine thicket communities. Infrastructure development may also destroy plants or disturb or fragment remaining habitat (Fensham, 1996; Calvert et al. 2005; DSEWPC, 2012). - Status notes
- Croton magneticus is listed as Vulnerable under the Queensland Nature Conservation Act 1992.
- Management documents
- Department of Sustainability, Environment, Water, Population and Communities (DSEWPC) (2012). Croton magneticus in Species Profile and Threats Database, Department of Sustainability, Environment, Water, Population and Communities, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 16 Feb 2012 13:24:13 +1100.
- Management recommendations
- DSEWPC (2012) documents regional and local priority actions to support the recovery of Croton magneticus. A summary of these include: avoid habitat loss, disturbance and modification (e.g. monitor known populations, control access routes, minimise land use impacts); manage fire (suitable fire management strategies); control invasive weeds (develop and implement a management plan in conjunction with existing local and national weed management plans for Lantana); enable recovery of additional sites and/or populations (e.g. undertake appropriate seed collection and storage (e.g. undertake appropriate seed collection and storage).
- Notes
- Occurs in the following Queensland pastoral districts: North Kennedy, South Kennedy (Queensland Herbarium, 2012). The species was previously listed as vulnerable under the EPBC Act 1999.
- References
- Calvert, G.A., Lokkers, C. and Cumming, R. (2005). Rare plants of Townsville-Thuringowa. Coastal Dry Tropics Landcare Inc., Townsville.
Department of Sustainability, Environment, Water, Population and Communities (DSEWPC) (2012). Croton magneticus in Species Profile and Threats Database, Department of Sustainability, Environment, Water, Population and Communities, Canberra. Accessed 16/02/2012. http://www.environment.gov.au/sprat.
Fensham, R.J. (1996). Land clearance and conservation of inland dry rainforest in north Queensland, Australia. Biological Conservation, 75: 289-298.
Forster, P.I. (2003). A taxonomic revision of Croton L. (Euphorbiaceae) in Australia. Austrobaileya 6 (3): 349-436.
Queensland Herbarium (2012). Specimen label information. Queensland Herbarium. Accessed 16/02/2012. - Profile author
- Lynise Wearne (16/02/2012)
Other resources
Data source
This profile data is sourced from the QLD Wildlife Data API using the Get species by ID function used under CC-By 4.0.
https://apps.des.qld.gov.au/species/?op=getspeciesbyid&taxonid=11493.
This information is sourced from the WildNet database managed by the Queensland Department of Environment and Science.
