Seeds of South Australia
Cymbopogon obtectus (Gramineae)
Silky-heads Lemon Grass
List of species for Cymbopogon
Click on an image to enlarge it
Seed collecting:
July to December
Herbarium regions:
North Western, Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Murray, Southern Lofty
NRM regions:
Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Eyre Peninsula, South Australian Arid Lands, South Australian Murray-Darling Basin
IBRA regions
SUMMARY
Fleurieu (KAN02)Kanmantoo
 Rare   (IUCN: RA d(ii))
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Rare   (IUCN: RA d(ii))   (Probable Decline)   [needs rich soils]
Olary Spur (FLB03) 
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)
Southern Flinders (FLB04) 
 Rare   (IUCN: RA d(i,ii))
Northern Flinders (FLB05) 
 Rare   (IUCN: RA d(ii))   (Probable Decline)   [grazing, ferals, weeds]
Central Flinders (FLB06) 
 Rare   (IUCN: RA d(ii))   (Probable Decline)   [grazing, ferals, weeds]
Eyre Hills (EYB03)Eyre Yorke Block
 Rare   (IUCN: RA d(i,ii))
Eyre Mallee (EYB05) 
 Rare   (IUCN: RA d(i,ii))
Murray Scroll Belt (RIV06)Riverina
 Endangered   (IUCN: EN B2ab(i,ii,iii,iv))   (Probable Decline)   [highly localised; does not tolerate salinity]
Myall Plains (GAW01)Gawler
 Rare   (IUCN: RA d(i,ii))
Gawler Volcanics (GAW02) 
 Least Concern
Gawler Lakes (GAW03) 
 Rare   (IUCN: RA d(i,ii))
Kingoonya (GAW05) 
 Rare   (IUCN: RA d(i,ii))
Kintore (GVD04)Great Victoria Desert
 Least Concern
Tallaringa (GVD05) 
 Rare   (IUCN: RA d(ii))   [limited habitat]
Bimbowrie (BHC05)Broken Hill Complex
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)
Sturt Stony Desert (CHC02)Channel Country
 Near Threatened   (Probable Decline)   [cattle]
Coongie (CHC06) 
 Rare   (IUCN: RA d(ii))
Lake Pure (CHC07) 
 Least Concern
Mann-Musgrave Block (CER01)Central Ranges
 Least Concern
Watarru (CER02) 
 Least Concern
Everard Block (CER03) 
 Least Concern
Tieyon (FIN03)Finke
 Least Concern
IBRA regions
DISPLAY ALL
Fleurieu (KAN02)KanmantooRare
  (IUCN: RA d(ii))
5 of 6 subregionsFlinders Lofty BlockRare
2 of 5 subregionsEyre Yorke BlockRare
Murray Scroll Belt (RIV06)RiverinaEndangered
  (IUCN: EN B2ab(i,ii,iii,iv))   (Probable Decline)   [highly localised; does not tolerate salinity]
4 of 8 subregionsGawlerLeast Concern
, Rare
2 of 4 subregionsGreat Victoria DesertLeast Concern
, Rare
Bimbowrie (BHC05)Broken Hill ComplexRare
  (IUCN: RA d(i,ii))   (Probable Decline)
3 of 4 subregionsChannel CountryLeast Concern
, Near Threatened
, Rare
3 of 3 subregionsCentral RangesLeast Concern
Tieyon (FIN03)FinkeLeast Concern
RSCA map:
Regional Species Conservation Assessments per IBRA subregion. Please click the thumbnail map.
AVH map:
Australian distribution map (external link)
SA Census:
Census of South Australian plants (external link)     [genus Cymbopogon]
Name derivation:
Cymbopogon from the Greek 'kymbe' meaning a boat and 'pogon' meaning a beard; alluding to the boat-shaped spatheoles subtending the hairy racemes. Obtectus
Distribution:
Found mainly in the northern part of South Australia with disjunct distribution in the southern Mount Lofty Ranges, growing near watercourses. Also found in all mainland states. Maybe extinct from Victoria.
Status:
Native. Common in South Australia. Very rare or extinct in Victoria. Common in the other states.
Plant description:
A handsome scented grass, to 90 cm high. Leaf blades narrow but usually flat, tapering to a long fine point, ligule 3-5 mm long, glabrous, nodes glabrous. Flower-spike shortly branched panicle, finally bent downwards, emerging from a sheathing bract, densely silky-villous owing to the long hairs arising from the pedicels and articles of the rhachis and almost completely concealing the spikelets and awns; first glume of fertile spikelet 5-nerved between the keels; somewhat obtuse; second glume with a central keel expanded into a narrow wing; awn inconspicuous, very slender, less than 1 cm long.  Flowering between March and September.
Fruit type:
Fertile lemma 3.6–4.5 mm long, without keel, 1–3 -nerved. Lemma apex lobed, awned, 1 -awned. Median
(principal) awn from a sinus, 6–8 mm long overall, without a column or with a straight or slightly twisted column. Palea absent. Anthers 3.
Seed type:
Yellow grain to 2.5 mm long.
Embryo type:
Lateral.
Seed collecting:
Use hands to gently strip seeds off the mature seed spike that are fluffy from the hairs and turning straw colour. Mature seeds will come off easily. Alternatively, you can break off the whole seed spike.
Seed cleaning:
Place the seeds/spike in a tray and leave to dry for two weeks. No further cleaning is required if only seed collected. If seed spikes collected, use hand to strip off the mature seeds. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.
Seed viability:
From one collection, the seed viability was low, ar 45%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
9000 (23.9 g)
9250 (24.1 g)
~5026-Oct-2004DJD 21
Gairdner-Torrens
28-Mar-200645%
Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.
Number of plants: This is the number of plants from which the seeds were collected.
Collection location: The Herbarium of South Australia's region name.
% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
August 201588%7d7d soak in 200 mg/L potassium nitrate for 48 hrs
1% water agar
Incubated under spring/autumn conditions
August 201584%14d14d None
1% water agar
Incubated under winter conditions
August 201578%7d7d soak in 500 mg/L gibberellic acid for 48 hrs
1% water agar
Incubated under winter conditions
August 201578%7d14d None
1% water agar
Incubated under spring/autumn conditions
August 201576%7d7d Soak in 500 mg/L gibberellic acid
1% water agar
Incubated under spring/autumn conditions
August 201574%7d14d soak in 200 mg/L potassium nitrate for 48 hrs
1% water agar
Incubated under winter conditions
Result: Maximum percentage of germination observed.
T0: Number of days before first germinant observed.
T50: Number of days to achieve 50% germination.
Pre-treatment: The initial treatment that the seeds received prior to placement on germination media.
Germination medium: The substrate that seeds were placed on for the duration of the germination experiment.
Incubator conditions:
Photoperiod: The duration of light exposure that the seeds were subject to during a 24 hour period.
Thermoperiod: The constant or diurnal temperatures that seeds were subject to during a 24 hour period.
Winter conditions: 15°C 20 h (3am→11pm); 5°C 4 h (11pm→3am) / 10 h light (8am→6pm); 14 h dark (6pm→8am)
Spring/Autumn conditions: 22°C 12 h (8am→8pm); 10°C 12 h (8pm→8am) / 12 h light (8am→8pm); 12 h dark (8pm→8am)
Summer conditions: 30°C 14 h (6am→8pm); 15°C 10 h (8pm→6am) / 14 h light (6am→8pm); 10 h dark (8pm→6am)