18. Tragopogon luteum Ger. 595. Raii Syn. 171. Tragopogon pratense Sp. pl. 789. _Yellow Goats Beard_, or _Go-to-bed-at-noon_. The latter of these names was given to this plant long since, on account of this remarkable property. The flowers open in general about three or four o’clock, and close again about nine or ten, in the morning. These flowers will perform their _vigiliæ_, if set in a phial of water, within doors for several mornings successively; and I have sometimes observed them to be quite closed, from their utmost state of expansion, in less than a quarter of an hour. It flowers in June. 19. Tragopogon gramineis foliis, hirsutis. C. B. pin. 275. Raii. Hist. Plant. 253. _Rose-coloured Goats Beard._ These open between five and six in the morning, and close about eleven. Tragopog. hybridum Sp. plant. 789. 20. Tragopogon, calycibus corolla brevioribus inermibus, foliis lyrato-sinuatis. Hort. Ups. 244. Sp. pl. 790. Hall. Hort. Gotting. 2. p. 419. The flowers of this plant open at six or seven in the morning, and shut between the hours of twelve and four in the afternoon. 21. Sonchus Tingitanus papaveris folio. Tourn. Raii Suppl. 137. Scorzonera Tingitana Sp. pl. 791. _African Sowthistle with a poppy leaf._ This plant opens its flowers between four and six in the morning, and closes them in about three hours. 22. Sonchus repens, multis hieracium majus J. B. II. 1017. Raii Syn. 163. Sonchus arvensis Sp. pl. 793. _Tree Sowthistle._ These flowers expand about six or seven, and close between eleven and twelve in the forenoon. This is common in corn-fields, and flowers in June, July, and August. 23. Sonchus lævis Ger. Raii Syn. 161. Sonchus oleraceus Sp. pl. 794. _Smooth or unprickly Sowthistle, Hares Lettuce._ These open about five in the morning, and close again at eleven or twelve. 24. Sonchus lævis laciniatus cæruleus C. B. pin. 124. Raii Hist. pl. 225. Sonchus alpinus Sp. pl. 794. _Blue-flowered Mountain Sowthistle._ These open about seven, and close about noon. 25. Sonchus tricubitalis, folio cuspidato Merr. pin. Raii Syn. 163. Sonchus asper arborescens C. B. pin. 124. Sonchus palustris Sp. pl. 793. _The greatest Marsh tree Sowthistle._ It expands its flowers about six or seven, and closes them about two in the afternoon. 26. Lactuca sativa C. B. pin. 122. Sp. pl. 795. _Garden Lettuce_, opens its flowers about seven, and closes them about ten, in the forenoon. 27. Dens leonis Ger. 228. Raii Syn. 170. Leontodon Taraxacum Sp. pl. 798. _Dandelion._ It expands at five or six, and closes at eight or nine, in the forenoon. This flowers early in the spring, and again in the autumn. 28. Dens leonis hirsutus leptocaulos, Hieracium dictus. Raii Syn. 171. Leontodon hispidum Sp. pl. 799. _Rough Dandelion_, or _Dandelion Hawkweed_. This plant opens its flower about four in the morning, and keeps it expanded till three in the afternoon. In May.