Common names
Eastern Bitter-cress
Etymology
Cardamine from the Greek 'kardamon', a name given by Dioscorides for a species of cress, an Indian spice and derived from the Greek 'cardia' meaning heart and 'damaein' meaning to blind, alluding to the reputed heart-strengthening effects of the plant. Microthrix from the Greek 'mikros' meaning small and 'thrix' meaning hair, referring to the minute hairs on the leaves.
Distribution and status
Found in the southern Mount Lofty Ranges in South Australia, growing in moist habitats near creeks and low-lying areas. Also found in New South Wales and Victoria. Native. Rare in South Australia. Rare in Victoria. Common in New South Wales.
Herbarium regions: Southern Lofty, Green Adelaide
AVH map: SA distribution map (external link)
Plant description
Annual herb to 30 cm high with a taproot or fibrous root and stems erect to trailing, glabrous or occasionally sparsely hairy. Basal leaves few to many, persisting or not, to 8 cm long, simple or pinnate, the terminal pinna relatively large, broadly ovate with a strongly cordate base. Stem leaves mostly to 5 cm long, pinnate with 1-3 pairs of lateral pinnae, terminal pinnae usually 5-9-lobed, often acutely, lateral pinnae usually trilobed, margins of pinnae almost always with several minute hairs. Flower spike few to many white flowers. Flowering September and December. Fruits are long pale brown pods to 3 cm in length, splitting into two. Seeds are small orange-brown flat reniform seeds to 1.5 mm long and 0.7 mm wide. Seed embryo type is bent.
Seed collection and propagation
Collect seeds between October and January. Collect maturing pods those turning pale brown with orange seeds inside. Be gentle with the pods as they split open easily. Place the pods in a tray and cover with paper to prevent seeds from popping out and leave to dry for a week. Then rub the dried pods gently by hand to dislodge the seeds. Use a sieve to separate the unwanted material. 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 is high for this species. This species has physiological dormancy that need to be overcome for the seed to germinate.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| MSB | 6,000 (1.46 g) | 100+ | 11-Jan-2007 | RJB71131 Southern Lofty | |||
| BGA | 3,800 (0.82 g) | 27-Apr-2007 | RJB70361 Southern Lofty | 1-Aug-2007 | 95% | +5°C, -18°C | |
| BGA MSB | 4,800 (0.78 g) 4,800 (0.78 g) | 50+ | 4-Dec-2007 | TST259 Southern Lofty | 19-Sep-2008 | 100% | +5°C, -18°C |
| BGA | 230 (0.181 g) | 30+ | 28-Oct-2021 | DJD4063 Southern Lofty | 7-Jul-2022 | 98% | -18°C |
| BGA | 2,400 (0.359 g) | 30+ | 28-Oct-2021 | DJD4056 Southern Lofty | 7-Jul-2022 | 100% | -18°C |
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.