134 ANGJOSPERMAE—DICOTYLEDONES 



bees and bees) alight upon the corolla they irritate the stamens, which move outwards 

 and dust them with pollen, that they frequently transfer to the stigmas of other 

 flowers, especially those in which the style protrudes laterally from the bundle of 

 stamens. Automatic self-pollination is usually excluded, for the stigma projects 

 0-5-0-7 beyond the anthers of the surrounding stamens. Besides the ordinary plants 

 with hermaphrodite flowers only, andromonoecious ones have been observed, bearing 

 male flowers in the proportion of one to fifty or eighty of the usual kind. Kirchner 

 says that the male flowers are smaller than the others, with fewer stamens, and no 

 pistil. 



333. H. cantini Dun. — According to Briquet (op. cit.), the protogynous pollen 

 flowers of this species, which are visited by humble-bees and bees, open and close 

 by movement of the sepals. The filaments are not irritable. The diameter of the 

 bright yellow corolla is 12-13 '^™' when fully expanded. Kirchner says that 

 automatic self-pollination very rarely takes place, as the flowers are protogynous 

 and the anthers extrorse. 



334. H. kahiricum Delile, and 335. H. Lippii Pers. — These two Egyptian 

 species frequently possess cleistogamous flowers, according to Ascherson (Bui. see. 

 linn., Paris, i, i88o, pp. 250-1 ; Sitzber. Ges. natf. Freunde, Berlin, 1880, pp. 97-108). 



336. H. villosum Thib., and 337. H. ledifolium L. — Ascherson (Sitzber. 

 Ges. natf Freunde, Berlin, i, 1880) says that the flowers of these species open and 

 are cross-pollinated only in the morning. If crossing is not then eff'ected, self- 

 pollination is brought about by closure of the flower. The same applies to species 

 of the genus 



lU. Cistus Tourn. 

 338. C. hirsutus L. and 339. C. villosus L. 



Visitors of C. villosus. — Schletterer observed the following bees, po-cltg., at 

 Pola.— 



I. Andrena convexiuscula K. ; 2. A. cyanescens Nyl. ; 3. A. nana K. ; 4. Halictus 

 calceatus Scop., var. obovatus K. ; 5. H. fasciatellus Schenck ; 6. H. interruptus Pz. ; 

 7. H. levigatus K.t>\ 8. H. minutus K.; 9. H. quadrinotatus K.; 10. H. scabiosae 

 Rossi; II. H. tetrazonius A7a^; 12. H. varipes iJ/cir. 



340. C. monspeliensis L. — 



Visitors. — Schletterer observed the following bees at Pola. — 



I. Andrena cyanescens Nyl.; 2. A. morio Brull.; 3. A. nana K.; 4. Ceratina 



cucurbitina 7?wj/; 5. CoUetes lacunatus Dours; 6. Halictus calceatus Scop.; 7. H. 



minutus K.; 8. H. morio F. ; 9. H. quadrinotatus K.; 10. H. scabiosae Rossi; 11. 



Prosopis clypearis Schenck; 12. P. genahs Ths.; 13. P. variegata F. 



341. C. salvifolius L. (Knuth, ' Bl. u. Insekt. a. d. Ins. Capri.') — The flower — 

 which smells slightly of jessamine — expands in the sunshine into a disk 5 cm. in 

 diameter. There are yellow pollen-guides on the bases of the white petals. The 

 anthers of the numerous stamens have already dehisced when the flower opens, and 

 the large capitate, strongly papillated stigma is simultaneously mature. The stamens 

 at first lie upon the recurved petals, but subsequently become erect, so that the 

 anthers are brought above the stigma, when automatic self-pollination may take 



