Seeds of South Australia
Picris squarrosa (Compositae)
Hawkweed Picris
List of species for Picris
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Herbarium regions:
Murray, Southern Lofty
NRM regions:
Adelaide and Mount Lofty Ranges, South Australian Murray-Darling Basin
IBRA regions
Fleurieu (KAN02)Kanmantoo
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [highly localised]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [4 old records; only recorded around Pt Noarlunga]
St Vincent (EYB02)Eyre Yorke Block
 Endangered   (IUCN: EN D)   (Definite Decline)   [Weedy looking plant, growing on coast. Threatened by coastal development.]
Murray Mallee (MDD02)Murray Darling Depression
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [restricted to river]
Murray Scroll Belt (RIV06)Riverina
 Rare   (IUCN: RA ab)   (Probable Decline)   [river spp]
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 Picris]
Name derivation:
Greek 'pikros' sharp, pungent and Latin 'squarrosus' scabby bot, having overlapping leaves or bracts that are pointed or recurved
Distribution:
On coastal dunes, alluvium along rivers, and disturbed ground elsewhere
Status:
Rare
Plant description:
Erect biennial or perennial 20–80 cm high. Basal leaves elliptic to narrowly lanceolate, 6-22 cm long, 1-3 cm wide, hispidulous to hispid; cauline leaves lanceolate to linear decreasing in size up the stem. Inflorescence a loose terminal corymb, heads 5-9mm in diameter. Florest bisexual, with ligules 5–8 mm long, yellow. Flowering July - December.
Fruit type:
Achene 7-9 mm long, narrowed towards the apex but never filiform-beaked, ribbed, brown to yellowish; pappus bristles cream, mostly 7-9 mm long
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
Jun-1390%6 d6 d
1% agar with 250 mg/L gibberellic acid (pH 6.5);
Incubated under winter conditions
Jun-1388%6 d6 d
1% agar;
Incubated under spring/autumn conditions
Jun-1386%6 d6 d
1% agar with 250 mg/L gibberellic acid (pH 6.5);
Incubated under spring/autumn conditions
Jun-1384%6 d6 d
1% agar with 100 mg/L potassium nitrate;
Incubated under winter conditions
Jun-1380%6 d6 d
1% agar;
Incubated under winter conditions
Jun-1378%6 d6 d
1% agar with 100 mg/L potassium nitrate;
Incubated under spring/autumn 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)