Family: Gentianaceae
Blackstonia perfoliata
Citation:
Hudson, Fl. Angl. 146 (1762).
Synonymy: Gentiana perfoliata L., Sp. Pl. 232 (1753); Chlora perfoliata (L.)L., Syst. Nat. edn 12, 2:267 (1767).
Common name: Yellow-wort, yellow centaury.
Description:
Stiffly erect annual to 25 cm high, with a little-branched inflorescence at the apex, with terete branches, glabrous, with a distinct basal rosette; basal leaves densely clustered, oblanceolate to elliptic, 3-12 x 2-4 mm, rounded or obtuse, spreading to recurved, withering early; cauline leaves ovate to almost triangular, 8-25 x 6-14 mm, acute to pointed, connate for up to about one-third of their length, spreading at about right angles to the stem, perfoliate.
Inflorescence a thyrse with 1-3 dichasia each with 1-5 flowers but opposite ones often developing unequally; sepals fused for up to 2 mm, linear to linear-lanceolate, 6-15 mm long, pointed, spreading to erect after flowering; corolla short-tubular, yellow; tube 4-7 mm; lobes lanceolate to elliptic, 3-7 mm long, acute to obtuse; stamens with the filaments fused to the corolla tube; ovary ellipsoid, tapering into a thin style, with 2 bifid stigmas.
Septicidal capsule releasing seeds for more or less their whole length.
Published illustration:
Ross-Craig (1964) Drawings Brit. Pl. 20:pl. 26.
Distribution:
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Moist places.
S.Aust.: EP, SE. Native to Europe and the Mediterranean.
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Conservation status:
naturalised
Flowering time: Nov.
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SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia
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Biology:
No text
Taxonomic notes:
If one mainly uses the character that the upper cauline leaves are not or scarcely constricted towards the base and fused around the stems then all the S.Aust. material should be identified as subsp. perfoliata (cf. Turin (1972) Fl. Europaea 3:56). The branches of the few-flowered dichasia are usually unequal and the calyx lobes are linear-lanceolate and often as long as the corolla which are usually characteristics of subsp. serotina (Koch ex Reichenb.)Vollmann.
Author:
Not yet available
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