Blackstonia named after John Blackstone (1712-1753), an English apothecary and botanist. Perfoliata from the Latin 'per' a prefix meaning through and 'folium' meaning a leaf; referring to the base of the leaf which is fused around the stem so that the leaf appears to pass through it.
Distribution and status
An introduced species native to Europe and the Mediterranean region and recorded on the southern Eyre Peninsula and the South-east in South Australia, growing on shallow soils derived from limestone. Also recorded in Victoria. Introduced. Uncommon in South Australia and Victoria.
Herbarium regions: Eyre Peninsula, South Eastern
NRM regions: Eyre Peninsula, South East
AVH map: SA distribution map (external link)
Erect annual to 25 cm high with a distinct basal rosette. Basal leaves densely clustered, oblanceolate to elliptic, to 12 mm long and 4 mm wide, rounded or obtuse, withering early. Upper leaves ovate to almost triangular, to 25 mm long and 14 mm wide, perfoliate. Inflorescence 1-3 terminal spike with bright yellow flowers. Flowering between November and February. Fruits are brown ellipsoid capsule to 8 mm long, remaining enclosed in enlarged corolla-tube. Seed embryo type is spatulate under-developed.
Seed collection and propagation
Collect seeds between January and March. Collect mature capsules as they dry off and turn brown. They should contain hard 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.