200 



ANGIOSPERMAEDICOTYLEDONES 



2142. M. pratense L. (Herm. Mtiller, ' Fertilisation/ pp. 458-61, ' Weit. Beob.,' 

 Ill, p. 36 ; Kirchner, ' Flora v. Stuttgart,' pp. 594-5 ; MacLeod, Bot. Jaarb, 

 Dodonaea, Ghent, v, 1893, pp. 354-6 ; Loew, 'Bliitenbiol. Floristik,' p. 399 ; Knuth, 

 'Bliitenbiol. Beob. a. d. Ins. Riigen,' ' Bloemenbiol. Bijdragen.') The horizontal 

 flowers of this species possess a yellowish-white three-edged corolla-tube 14-15 mm. 

 long, which conceals a large quantity of nectar in its base, rising to a height of 

 2-3 mm. The nectary expands towards the lower lip into a whitish rounded body, 

 on either side of which runs a nectar-secreting groove. A circlet of converging hairs 

 protects the secretion from rain, which, owing to the protruding lower lip, is able to 

 penetrate into the flowers in spite of their horizontal position. The corolla-tube is 

 widened in front for a distance of 4-5 mm. sufiiciently to permit of the easy insertion 



Fig. 303. Melamfyrum pratense, L. (after Henn. MOlIer). (i) Flower seen from the side (x j). 

 (2) Do., from above. (3) Do., from the front (x 7). (4) Pollen-receptacle formed by the anthera, 

 from behind. (5) Do., after opening, from the front. (6) The two stamens of the right half of the 

 flower, seen from the left. (7) Relative position of the stigma and pollen-receptacle, a, lateral fold 

 of the anterior part of the corolla ; b, nectar-guide ; c, stigma ; </, hairy covering of the pollen-receptacle ; 

 , teeth of the filaments ; f, spine-like appendages of the anthers. 



of the head of a humble-bee. In this widened part a fold projects inwards from ti 

 lower part of each side-wall, abutting upon the under-side of the tube so as to reduce 

 the opening of the flower to a breadth of scarcely 3 mm. The height of this is 

 narrowed to 1-2 mm. by two dark-yellow protrusions of the lower lip, serving as 

 nectar-guides, and by a contraction behind the upper lip. But the two lateral folds 

 can be separated by the head of a humble-bee, giving it plenty of room. After the 

 head is thus inserted, a proboscis lo-ii mm. long is required to get at the nee 



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