312 THE BOTANICAL EXCHANGE CLUB OF THE BRITISH ISLES. 



tudinal resinous ridges, without resinous pustules (query in all forms 

 of H. Desetangsii 1 ) 



2. Angles of the stem not or scarcely winged. Leaves elliptic, 

 more or less narrowed towards the base, sessile, with comparatively 

 large pellucid glandular dots, or also without any such. Petals golden 

 yellow, considerably longer than the calyx (mostly 2 — 3 times as long). 



3. Sepals broadly or narrowly ovate-lanceolate, acute or tapering. 

 Occasional forms of Desetangsii with obtuse sepals are dis- 

 tinguished from maculatum by the more feebly developed secondary 

 ridges of the stem, the less sharply pellucid net-nervation of the leaves, 

 the larger flowers, and also by the later time of flowering : thus at the 

 end of August 1911 at Freiburg maculatum was completely over whilst 

 Desetangsii and perforatum were still in flower. Flowers mostly as 

 large as in H. perforatum. Petals about 12 — 15 mm. long. — //. 

 Desetangsii Lamotte. 



3.* Sepals ovate or elliptic, roundly obtuse, or somewhat toothed, 

 and then almost acute. Flowers smaller : petals (with us) mostly not 

 above 10 mm. long, with black glandular dots. Leaves with strong 

 pellucid thick net-nervation.- — 11. maculatum Cr. (//. quadrangulum 

 auct.) 



2.* Angles of stem (in normally developed specimens) distinctly 

 winged. Leaves with the broadened base semi-amplexicaul, always 

 dotted, with very numerous delicate pellucid glandular dots. Sepals 

 lanceolate, acute : petals bright yellow, not black-dotted, a little longer 

 than the calyx (scarcely up to twice as long), mostly about 8 mm. 

 long. — //. acutum Moench (H. tetrapterum Fr.) 



On account of its morphologically intermediate position the 

 Hypericum we are now dealing with has received from various 

 botanical authors a totally different value and explanation. 



Hypericum Desetangsii was consequently regarded (so far as it 

 was not confounded with H. quadrangulum, i.e., maculatum, as was 

 universally the case with the older authors) sometimes as a true 

 species (Bellynck, Callay, Grenier, Lamotte, Bonnet, Focke, Burnat, 

 Coste, Schinz) standing either between perforatum and maculatum 

 (Liamotte, Schinz), or between maculatum and acutum (Bonnet, Focke, 

 Burnat, Coste) sometimes as a variety or sub-species of perforatum, of 

 acutum, or of maculatum (quadrangulum) — finally, as a hybrid, 

 maculatum x perforatum* or acutum x perforatum, or else acutum x 

 maculatum. 



