466 



ANGIOSPERMAE—MONOCOTYLEDONES 



pendulous bells the style projects up to 2 mm. beyond the anthers. Pollen-collecting 

 bees therefore first touch the stigma and then the anthers, so that cross-pollination is 

 ensured by insect-visits. Should these fail, automatic self-pollination takes place by 

 the fall of pollen upon the papillose edge of the stigma. 



Besides the usual form with bright 

 yellow anthers and pure white perianth, 

 Ludwig observed another in Thuringia 

 with vivid yellow anthers and certain 

 parts of the flower coloured red, such 

 as the base of the perianth, hypogynous 

 disk, or the base of the filaments. Lud- 

 wig states that this large-flowered form 

 secretes free nectar on the disk situated 

 .) Fro.Srsefrretr;rXt;^'^'" "rsef^l'ri ^elow the ovary, so that it appears to be 



the side after removal of half the perianth with three of the entomophilous tO a greater degree than 

 epipetalous stamens, a, anthers; /r, ovary; ii, stigma; ,. r> ^ ^ ^ 



j(', filaments. the Ordinary One. Schulz, however, says 



that this is not the case, as in both forms 

 the flowers are of the same size, and the hypogynous disk is provided with sugary 

 juice without secretion of free nectar. 



Visitors. — Knuth observed the honey-bee,, freq., po-ckg. Herm. Miiller records 

 the honey-bee, and also (in the Alps) the Cerambycid beetle Acmaeops collaris L. 



902. Polygonatum Adans. 



Homogamous humble-bee or bee flowers, white in colour, with a greenish tip. 

 Nectar secreted, usually in large quantities, by the septal glands of the ovary, and 

 stored at the base of the perianth. 



Fig. 404.. Poly^onaiUfH veritcilialum, AIL i,i.h^T\{^Tm.^ii\\^r). A. Flower, seen directly from 



below ( X 7). B. Do., in longitudinal section. C. Pistil, h, nectar ; ov, c»vary ; p, petals : s, sepals ; 



St, stigma. 



2805. P. verticillatum All. (= Convallaria verticillata Z.). (Herm. Miiller, 

 ' Alpenblumen,' pp. 52-3; Schulz, ' Beitrage,' II, pp. r66, 224; Grassmann, 



