THYMELAEACEAE 359 



deeply. Neither nectar nor nectary has been observed. The flowers set abundant 

 fruits. 



Visitors. These are Lepidoptera and flies, which must effect autogamy 

 (Kirchner). 



775. Thymelaea Tourn. 

 Flowers with concealed nectar. 



2508. T. calycina Meissn. (= Passerina calycina DC). The flowers of this 

 species are greenish-yellow in colour. 



Visitors. MacLeod (Pyrenees) saw a fly and a po-dvg. beetle. 



2509. T. arvensis Lam. (= T, Passerina Lange, Stellera Passerina L., and 

 Passerina annua Wikstr.). (Kerner, 'Nat. Hist. PI.,' Eng. Ed. i, II, pp. 174, 365.) 

 Kerner says that self-pollination does not take place at first in the small, nectar- 

 scented flowers of this species, as the sticky, clinging pollen does not fall automatically 

 upon the stigma. At this time cross-pollination by insect-visits is possible. Towards 

 the end of anthesis, however, the perianth contracts, so that the anthers are pressed 

 against the stigma and autogamy is effected. If the weather is unfavourable the 

 flowers do not open, and hemi-cleistogamoiis fertilization takes place. 



2510. T. dioica All. (= Passerina dioica Ram.), and 2511. T. tinctoria Endl. 

 (= P. nivalis Ram). (Midgeville, Bull. soc. bot., Paris, xxxv, 1887.) Mi^geville 

 describes small sterile and large fertile flowers in these species. 



776. Leucosmia Benth. 



Darwin (' Diffierent Forms of Flowers ') and Hildebrand (' D. Geschlechts-Vert. 

 b. d. Pfl.') describe species of this genus as dimorphous. 



777. Pimelea Banks et Soland. 



2512. P. ferruginea Labill. (=P. decussata R.Br.). (Willis, J. Linn. Soc, 

 Bot., London, xxx, 1895.) Willis says that the odourless flowers of this species are 

 protandrous. 



Visitors. Willis observed flies in the Cambridge Botanic Garden. 



XCIV. ORDER ELAEAGNACEAE R.BR. 

 778. Hippophae L. 



Flowers anemophilous and dioecious. 



2513. H. rhamnoides L. (Kerner, 'Nat. Hist. PI.,' Eng. Ed. i, II, pp. 148, 

 150.) In the male flowers of this species the dusty pollen falls from the four anthers 

 into the base of the flower while still in the bud. Even after this has opened the 

 pollen is protected from rain by the two bowl-shaped bracts, which remain fastened 

 together at the apex : they only diverge laterally, so that two clefts are formed out 

 of which the pollen is shaken by gusts of wind, when it may be transferred to female 

 flowers. There is no nectar. 



Visitors. Verhoeff" (Norderney) observed a hover-fly (Syrphus ribesii Z.), 

 searching for pollen. 



