Knaiitia.] dipsace^e. 245 



mit of the ultimate divisions of tlie stem. Corolla not a line in diameler, white, 

 the segments tinged with pale pink, roundish entire. 



Order XLII. DIPSACE^, Juss. 



" Calyx-tahe adnate with the ovary, surrounded by a scariose 

 involucel closely investing the ovary and ripe fruit. Corolla with 

 the limb oblique, with an imbricated sestivation. Stamens 4 — 5 ; 

 anthers distinct. Ovary 1-celled. Style 1, filiform. Fruit dry, 

 indehiscent, 1-celled, with 1 pendulous seed, crowned with the 

 pappus-like calyx. Alhvmen fleshy. — Mostly herbaceous plants, 

 with opposite or whorled leaves. Flowers pedicellate, collected into 

 a dense head, which is surrounded by a many-leaved involucre. 

 Nearly allied to the Compo^itse." — Br. Fl. 



I. DiPSACUs, Linn. Teasel. 



" Receptacle with spinous scales. Involucel with a thickened 

 limb, forming a crown to the ovary. Calyx cup-shaped. Stamens 

 distinct, about equal. Fruit 4-angled, with 8 pores or depressions. 

 (Leaves opposite)." — Br. Fl. 



1. D. sylvestris, L. Wild Teasel. "Leaves sessile undivided, 

 upper ones connate, scales of the receptacle straight at the extre- 

 mity, involucres curved upward." — Br. Fl. p. 195. E. B. t 10.33. 



p. Flowers white. 



By roadsides, along moist hedges, on ditchbanks, and in wet woods and 

 thickets; extremely common, i^/. July, August. $. 



j3. A few plants by the roadside between Calbourue and Shalfleet, with the 

 common blue kind, 1844. 



Seeds (achenia) brownish, sessile, finely downy with erect or appressed pubes- 

 cence, oblong-truncale, quadrangular, with 8 prominent ridges and as many deep 

 furrows, the summit with radiating fissures, bordered by the shallow persistent 

 outer calyx, and crowned by the more deciduous, substipitate and very hairy inner 

 one, each seed attached to the spongy receptacle at the base of a scale which 

 enfolds it on two of its faces. 



The water found collected within the cavity of the connate leaves must, I ima- 

 gine, be secreted or eliminated by the plant itself, since I observed it to be abim- 

 daiitly furnished, during the present unusually dry and hot season, June, 1846, 

 when no rain has fallen for some weeks, and very little dew has been deposited at 

 night, yet the water remains unevaporated by the intense heat of the sun's direct 

 rays. I have remarked, besides, that, on the same plant, whilst some of the leaves 

 held water in considerable quantity, others contained either very little or none at 

 all, which seems to point at a great inequality of the secreting activity of different 

 leaves or other parts of the individual plant. 



One of our tallest herbaceous plants ; I have seen it about Ejde nearly 7 feet 

 high. The flowers expand in successive rings or zones on the large oval heads, 

 commencing about the middle of each. 



II. Knautia, Linn. Knautia. 



" Receptacles hairy, without scales. Involucels with a 4-toothed 

 minute limb. Calyx cup-shaped, with radiating teeth. Stamens 



