Species profile—Plectranthus omissus
Classification
Plantae (plants) → Equisetopsida (land plants) → Lamiaceae → Plectranthus omissus
Sighting data
Species details
- Kingdom
- Plantae (plants)
- Class
- Equisetopsida (land plants)
- Family
- Lamiaceae
- Scientific name
- Plectranthus omissus P.I.Forst.
- WildNet taxon ID
- 9066
- Superseded by
- Coleus omissus (03/10/2019)
- Conservation significant
- No
- Confidential
- No
- Endemicity
- Exotic
- Pest status
- Nil
- Short Notes
- two sheets, status annotated by author
- Description
- Plectranthus omissus is a subshrub to 100 cm high, the foliage is slightly aromatic. The stems or lateral branches are erect to straggling, the lower parts are woody and up to 10mm thick; upper parts with sparse to dense, retrorse, 6 to 8-celled non-glandular silver trichomes up to 0.6 mm long but commonly much shorter, lacking glandular trichomes, with sparse sessile 4-celled glands. The leaves are a similar colour on both surfaces; the petioles are 25 to 36 mm long; the lamina is broadly ovate, 20 to 80 mm long by 30 to 60 mm wide, somewhat fleshy, serrate with 17 to 19 teeth on each margin; both surfaces with dense, retrorse, 6 to 8-celled non-glandular silver hairs, lacking glandular hairs, with sparse to dense sessile 4-celled glands. The flowers are in compact cymose clusters, arranged into terminal racemes 15 to 35 cm long. Clusters are 14 to 16-flowered; pedicels 3 to 3.5 mm long. The calyx is 2.6 to 2.8 mm long. The corolla is 8.5 to 8.8 mm long, lilac in colour; tube 4.8 to 5.0 mm long, abruptly curved at an angle of about 110 to 130 degrees about 1.4mm from the base, with scattered, divaricate, 4-6-celled non-glandular trichomes to 0.4 mm long, lacking glandular trichomes, with scattered sessile 4-celled glands; upper lobes subcircular, 2.4 to 2.5 mm long, 2.4 to 2.5mm wide; lateral lobes ovate, 1.0 to 1.2 mm long, and about 0.8 mm wide; the lower lobe oblong, 4.4 to 4.5 mm long, by 3.0 to 3.2 mm wide. The fruiting calyx is 4.0 to 4.8mm long; upper lobe lanceolate-triangular, 1.7 to 1.8 mm long by 1.2 to 1.4 mm wide; lateral lobes lanceolate-falcate, 1.3 to 1.5 mm long, about 1.2 mm wide; lower lobes lanceolate-falcate, 2.4 to 2.5 mm long by 0.5 to 0.6 mm wide. The seeds are hemi-spherical, 0.7 to 0.8 mm long, about. 0.7 mm wide by 0.4 mm thick (Forster, 1992).
Plectranthus omissus is closely related to P. argentatus, P. graniticola and P. torrenticola but is distinguished by the corolla tube (fused tubular part of the petal), which is shorter (4.8 to 5mm long) and has sessile (not stalked) glands as well as hairs (Forster, 1992; Queensland Herbarium, 2012). - Map
- View Map
- Distribution
- Plectranthus omissus is known from only five sites between the Conondale Ranges and Gayndah, Queensland. The population at one site is estimated to be only 30 to 40 plants (Halford, 1998). The species occurs within Conondale National park, Wratten Resource Reserve, Grongah National Park, Miva State Forest and Mudlo National Park (Queensland Herbarium, 2012).
- Distributional limits
- -25.8764687, 152.0935627
-26.672916, 152.8093931 - Range derivation
- Range derived from extent of the taxon's verified records
- Habitat
- Plectranthus omissus has been recorded on steep rocky outcrops approximately 300-400 m above sea level on the margin of vine forest or sclerophyll forests (Halford 1998).
- Threatening processes
- The main potential threats to P. omissus are inappropriate fire regimes (Halford, 1998) and increasing public access. Many of the sites where the plant occurs are infested by Lantana and Ageratum houstonianum (Forster, 1992; Queensland Herbarium 2012).
- Status notes
- Plectranthus omissus is listed as Endangered under the Queensland Nature Conservation Act 1992 (Queensland) and Endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
- Management recommendations
- Regional and local priority actions to support the recovery of Plectranthus omissus are outlined by DSEWPC (2012). A summary of these include: avoid habitat loss, disturbance and modification (e.g. monitor known populations to identify key threats; identify populations of high conservation priority); increase conservation information (raise awareness of Plectranthus omissus in the local community); control invasive weeds (e.g. develop and implement a management plan for the control of Lantana and Billy Goat Weed in the local region; identify and remove weeds in the local area, which could become a threat to the P. omissus, using appropriate methods); manage fire (e.g. develop and implement a suitable fire management strategy for P. omissus; and enable recovery of additional sites and/or populations (e.g. investigate options for linking, enhancing or establishing additional populations).
- Notes
- Occurs in the following Queensland pastoral districts: Wide Bay.
- References
- Department of Sustainability, Environment, Water, Population and Communities (DSEWPC) (2012). Plectranthus omissus in Species Profile and Threats Database, Department of Sustainability, Environment, Water, Population and Communities, Canberra. Accessed 31/05/2012. http://www.environment.gov.au/sprat.
Forster, P.I. (1992). Five new species of Plectranthus, L. Herit (Lamiaceae) from Queensland. Austrobaileya 3 (4):732-3.
Halford, D.A. (1998). Survey of Threatened Plant Species in south east Queensland Biogeographical Region. Queensland CRA/RFA Steering Committee.
Queensland Herbarium (2012). Specimen label information. Queensland Herbarium. Accessed 20/03/2012. - Profile author
- Ronald Booth (16/05/2012)
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=9066.
This information is sourced from the WildNet database managed by the Queensland Department of Environment and Science.
