BLACKSTONIA PERFOLIATA subsp.PERFOLIATA

Including:- Subsp. intermedia, differing only vaguely in quantitative characters

from Subsp. perjfoliata, being slender and small-flowered. It appears to have a

Mediterranean distribution

Family and Genus:- See- GENTIANACEAE

Common Name:- Yellow-wort

Homotypic Synonyms:- None

Meaning:- Blackstonia (L) For John Blackstone (1712-53) English apothacary and

botanical writer.

Perfoliata (L) The stem appearing to pass through the leaf blade.

Intermedia (L) Between extremes, intermediate.

General description:- An erect, short to medium, bluish- or grey-green annual.

Stems:-

1) 10-60 cm.

Leaves:-

1) Opposite, 5-30 mm, ovate to triangular.

2) Basal, obtuse, narrowed but not connate at the base.

3) Upper cauline, triangular, not or scarcely narrowed towards the base.

Flowers:-

1) 8-15 mm, 6- to 8-merous yellow.

2) Calyx-tube, very short.

3) Lobes, 6-12, linear 1-veined.

4) Lobes, of the stigma erect at anthesis, becoming patent later.

Fruit:-

1) A septicidal capsule. valves remain attached, not falling off.

Key features:-

1) Flowers, (6-)8-15 mm, 6- to 8-merous.

2) Upper cauline leaves, not or scarcely narrowed towards the base.

3) Calyx-lobes, linear.

Click here for a glossary of terms used.

Habitat:- Seasonally wet spots in scrubland vegetation, open dry shrubby

vegetation, sand dunes, also in moist bare sandy ground, streamsides, roadsides

and olive groves. 0-1200 m.

Distribution:- Widespread across the Mediterranean. Widespread and common on

Crete.

Flowering time:- Apr-Sept.

Photosby:- Steve Lenton