Botanical art
Prior names
Exacum ovatum
Common names
Yellow Centaury
Yellow Sebaea
Etymology
Sebaea named after Albertus Seba (1665-1736), a Dutch apothecary and botanist. Ovata from Latin meaning egg-shaped; referring to the shape of the leaves.
Distribution and status
Found in the southern part of South Australia, growing in woodland and shrubland on seasonally wet, sandy or gravelly soils, but also in drier, recently burnt sites. Also found in Western Australia, Queensland, New South Wales, Victoria and Tasmania. Native. Common in South Australia. Rare in Queensland. Common in the other states.
Herbarium regions: Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South Eastern, Green Adelaide
AVH map: SA distribution map (external link)
Plant description
Erect annual herb to 30 cm high, stem usually simple below inflorescence. Leaves broadly ovate, to 12 mm long and 10 mm wide. Inflorescence in sparse to mid-dense terminal clusters with tubular, yellow flowers. Flowering between September and November. Fruits are brown ovoid septicidal capsule releasing seeds only through the apex. Seeds are small black diamond-shaped seed to 0.4 mm long and 0.3 mm wide, with deep wrinkles and mesh-like surface. Seed embryo type is spatulate under-developed.
Seed collection and propagation
Collect seeds between October and December. Collect mature capsules as they dry off and turn brown. They should contain hard brown seeds inside. Place the capsules in a tray for a week. Then rub the capsules with your fingers to dislodge all the seeds. Use a sieve to separate the unwanted material. Be careful as the seeds are very small. 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. From two collections, the seed viability were high, at 100%.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| MSB | 19,000 (0.36 g) | 25 | 30-Oct-2007 | RJB75530 South Eastern | 100% | ||
| MSB | 7,000 (0.24 g) | 50+ | 18-Nov-2015 | JRG245 Kangaroo Island | 100% | ||
| BGA | 6,500 (0.065 g) | 100+ | 2-Nov-2015 | DJD3208 Northern Lofty | 2-May-2017 | 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.