OROBANCHACEAE 233 



Visitors. — I observed the honey-bee. Before creeping into the corolla, it first 

 examined a number of flowers from outside, flying from one to another and hovering 

 for some time like a Syrphid in front of the flower-entrance without touching it. Using 

 the large lower lip as a platform, it then crept far into the flower, touching, as 

 previously described, first the stigma and then the anthers. It soon emerged, 

 however, and repeated its attempts to obtain nectar from a number of other flowers, 

 thus effecting cross-pollination. As a matter of fact, this species of Orobanche does 

 secrete a certain amount of nectar at the orange-yellow base of the ovary. 



2187. O. ramosa L. (=Phelypaea ramosa C. A. Mey.). (Knuth, 'Blijten- 

 biol. Herbstbeob.' ; Kirchner, 'Flora v. Stuttgart,' p. 644; Warnstorf, Verh. bot. Ver., 

 Berlin, xxxvii, 1896.) — The flower mechanism of this species, which I was able to 

 observe as a root-parasite on hemp in the Kiel Botanic Garden, is the same as that 

 of the preceding species, but the corolla-tube is only 1 2 mm. long. Kirchner and 

 Warnstorf describe the odourless flowers as feebly protogynous. The trilobed lower 

 lip possesses shallower grooves than those of O. caryophyllacea. The mouth of the 

 flower is 3-4 mm. broad and 2^3 mm. high, but can become considerably wider by 

 the straightening out of its folds. The stigma projects beyond the free anthers, which 

 lie in two rows, each ending in two sharp processes. Cross-pollination is therefore 

 favoured at first, but insect-visits have not yet been observed. Automatic self- 

 pollination is rendered possible by the bending down of the front end of the style, 

 the stigma thus coming into contact with the pollen of the two anterior anthers. 

 Warnstorf describes the pollen-grains as small, white in colour, ellipsoidal, delicately 

 tuberculate, about 30 ju, long and 16-19 M broad. 



2188. O. purpurea Jacq. (=0. caerulea VilL, and Phelypaea caerulea C. A. 

 3fey.). (Knuth, ' Bestaubungseinricht. d. Orobancheen.') — I saw this plant on the 

 north shore of the Eckernforde as a root-parasite on Achillea millefolium, but in 

 spite of the conspicuousness of its large blue racemes, observed no insect-visits. 

 The flowers are odourless and nectarless, but their mechanism places them in class 

 Hb. At first the stigma projects beyond the anthers, but these soon reach the same 

 level, so that automatic self-pollination is effected. 



678. Cistanche Hoflfmgg. et Link. 



2189. C. lutea Hoffmgg. et Link (=Phelypaea lutea Desf.). (Trabut, Bui. soc. 

 bot., Paris, xxxiii, 1886, pp. 536-9.) — Trabut observed plants of this species in Oran, 

 a province of Algeria. They bore subterranean cleistogamous flowers with closed 

 tubular corollas. 



LXXVL ORDER LENTIBVLARIACEAE RICH. 

 679. Utricularia L. 



Yellow, herkogamous flowers, with sensitive stigmas ; belonging to classes Fh 

 and Hb (?). The lower lip is so close to the upper that the entrance to the flower is 

 closed. The former serves as an alighting-platform for insects, by the weight of which 

 it is depressed : it bears a nectar-yielding spur. The upper lip forms a shelter for 

 anthers and stigma. The latter is sensitive, and bends upwards and backwards after 

 having been touched by an insect. 



