J 24 



A NGIOSPERMAE—DICO T YLEDONES 



B. 



608. Nonnea JNIoench. 



1973. N. pulla DC. ( = N. erecta Bcmh.. and L3'copsis pulla Z.). — The flowers 

 of ihis species are of a dark or light purple-brown colour, rarely bright yellow or 

 almost white. 



Visitors. — Friese observed the following 7 bees in Hungary. — 



I. Eucera hungarica Friese i; 2. E. difilcilis Pe'rez; 3. E. interrupta Baer; 

 4. E. nitidiventris Macs. J; 5. E. parvicornis JIocs.-. 6. E. clypeata Er. $; 7. E. 

 chrysopyga Pe'r. S. 



Schulz noticed perforated flowers here and there at Halle (' Beitrage '). 



609. Symphytum Tourn. 



Honiogamous bee flowers ; with nectar secreted by an annular ridge at the base 

 of the ovary, and stored in the base of the corolla. According to Kerner, the 

 peduncle bends down in late anthesis, so that the flower assumes a nodding or 

 pendulous position, and the stigma is brought into the line of fall of the pollen, 

 thus rendering automatic self-pollination inevitable. 



1974. S. officinale L. (Sprengel, ' Entd. Geh.,' pp. 93-4 ; Herm. Muller, 

 'Fertilisation,' pp. 408-9, ' Weit. Beob.,' HI, p. 14; Kerner, 'Nat. Hist. PL,' Eng. 



Ed. I, II, p. 275; Kirchner, 'Flora v. 

 Stuttgart,' p. 556; Knulh, ' Bloemenbiol. 

 I^ijdragen ' ; Schulz, ' Beitrage,' II ; Loew, 

 ' Bliitenbiol. Floristik,' pp. 279-80.) — The 

 drooping flowers of this species are white or 

 violet-purple in colour, and their mechanism 

 ixsembles that of Borago. The bell-shaped 

 corolla is 14 mm. long, and it is contracted 

 above for a distance of 8 mm., so that only 

 long-tongued insects can suck the nectar 

 legitimately. At the junction of the narrow 

 and broader portions of the corolla there are 

 triangular hollow scales, alternating with the 

 filaments and covering the spaces between 

 them. The spiny edges of these appendages 

 prevent visitors from probing for nectar 

 between the filaments, and they are obliged 

 to insert their proboscis in such a way that 

 it must get dusted with pollen. 



The anthers cohverge to form a hollow cone surrounding the style, and they 

 dehisce introrsely in the bud, some of the pollen falling into the apex of the cone and 

 some remaining clinging to them. When an insect probes for nectar with its 

 proboscis the anthers are displaced and some of the pollen falls out. The projecting 

 stigma is the first part of the flower to be touched by a visitor, after which it is dusted 

 by pollen. The arrangement is favourable to crossing by insect-visits, but should 

 these fail automatic self-polhnation apparently takes place. Kerner states that the 

 flower is at first horizontal, but comes to droop in late anthesis owing to a bending 



Fig. 2]2. Symphytum officinale, L. (from 

 iiulure). . /. Flower seen from the side. B. Do., 

 ILirtly dissrctej. a, anthers, placed within the 

 hollow scales ; s, stirma. 



