UMBELLIFERAE 



471 



Visitors. — MacLeod saw 2 bumble-bees, an Eristalis, and 2 Muscids in the 

 Pyrenees. 



logg. E. alpinum L. — Christ states that the involucre of this species expands 

 at sunrise, and closes at sunset. 



iioo. E. amethystinum L. — 



Visitors. — Von Dalla Torre saw the wasp Vespa norwegica F. in the Tyrol, 

 where F. F. Kohl noticed 3 wasps (Eumenes pomiformis F.; Odynerus dantici 

 Rossi; Polistes gallica Z.). 



iioi. E. giganteum JBieb. — 



Visitors.— Loew saw a humble-bee in the Berlin Botanic Garden (Bombus 

 terrester Z., skg.). 



1102. E. planum L. — 



Visitors. — Loew observed the following in the Berlin Botanic Garden. — 



A. Diptera. {a) Muscidae: i. Lucilia caesar Z. {b) Syrphidae : 2. Eristalis 

 lenax Z.; 3. Syritta pipiens Z. ; 4. Syrphus corollae F. B. Hymenoptera. 

 Apidae : 5. Apis mellifica Z. 5, skg. 



323. Conium L. 



Flowers white in colour, arranged in compound umbels ; with exposed nectar. (All 

 the remaining genera of the order to be considered present these oecological characters, 

 except that the colour of the flowers may be yellow, greenish, or in some cases red.) 



1103. C. maculatum 

 L. (Herm. Muller, 'Fer- 

 tilisation, pp. 274-5, ' Weit. 

 Beob.,' I, p. 311 ; Knuth, 

 ' Bl. u. Insekt. a. d. nordfr. 

 Ins.,' pp. 79, 156.) — This 

 species will serve to illus- 

 trate the protandrous 

 flower mechanism which 

 characterizes most Umbel- 

 liferae. Several hundred 

 small white flowers are 

 aggregated into a large compound radiating umbel, which makes the plant very 

 conspicuous ; this inflorescence is borne on a stem which may be as much as a metre 

 high. The flowers are distinctly protandrous, and when the bud opens the stamens 

 are at first horizontal in position, and their anthers are unripe. They occupy the 

 intervals between the petals. They then successively become erect, so that the 

 upwardly dehisced anthers lie above the still immature stigmas. When an anther 

 has dehisced, its filament resumes the horizontal position, and another stamen 

 takes its place. All the stamens are completely withered as a rule before the stigmas 

 mature. The styles are then i mm. long, so that they are in the same position as 

 that occupied by the anthers during the first (male) stage of anthesis. Numerous 



Fig. 161. Coiiiiini macuia/inn, Z-. (after Hcrm. Muller). (l) Flower 

 at the beginning of the ^^^^t (male) stage. (2) Flower in tlie middle of the 

 same stage. (3) Flower in the second (female) stage. n^-n\ stamens; 

 ;/, nectary;, J/, stigma. 



