44 



ANGIOSPERMAE—DICOTYLEDONES 



4. Tribe Rhodoreae. 

 Homogamous or protogynous flowers, belong to the classes E, EC, and H. 



526. Phyllodoce Salisb. 



Ovoid, usually pendulous, blue or red bee flowers ; concealed nectar, secreted by 

 a yellow crenate ring at the base of the ovary. 



1769. P. taxifolia SaUsb. (=P. caerulea Bab., Erica caerulea Willd., E. 

 arctica Waitz and Bryanthus taxifolius^. Gray). (Warming, Bot. Tids., Kjobenhavn, 

 XV, 1885, pp. 20-5.) — Warming describes this northern species as feebly protogynous 

 in Greenland. The length of the style is variable, and the stigma becomes sticky 

 in the bud. In short-styled flowers the stigma and anthers are at the same level, 



so that automatic self- 

 pollination is inevitable. 

 The generally pendulous 

 position of the flowers, 

 and the narrow opening 

 of the corolla, suggest 

 adaptation to pollination 

 by bees, but these have 

 not so far been observed. 

 ].iessel only saw a butter- 

 lly (Colias boothii H.-Sch. 

 = C. hecla Le/.). [Cf. 

 Fig. 227.) 



The mechanism of 

 the flowers examined by 

 Lindman on theDovrefjeld 

 agreed essentially with 

 that of Greenland speci- 

 mens, but a form was 

 observed with a style only 2 mm. long, so that the anthers projected beyond the 

 stigma, excluding the possibility of self-pollination. 



Ekstam found the species to be protogynous-homogamous in the Swedish 

 Highlands. 



The specimens collected by Vanhoffen in Greenland mostly possessed homo- 

 stylous flowers, and fruits were set there at the end of July or the beginning of 

 August (Abromeit, ' Bot. Ergeb. von Drygalski's Gronlandsexped.,' p. 48). 



Fig. 22-]. Phyllodoce taxifolia. Salisb. (after E. Warming). Drawn 

 from Greenland specimens t./4, B. C. D. >: 2}). .ti. A 3'oung flower, just 



opened ; tliere are already some pollen-grains on the stigma. The hairs on 

 the llower and pedicel are omitted. £. Anotlier flower, in which anthers 



and stigma are at the same level. Most of the stamens have been removed. 

 C. A third young flower, in which the anther-pores and stigma are at the 

 same level, approximately between the upper and middle thirds of the 

 corolla. /?. Do., seen from the mouth of the hell. /T. Pistil and nectary, 

 seen en face. F. \ stamen, seen from the ront. G. \ pollen-tetrad, 



y/. Base of the pedicel, with bracteoles. 



527. Ledum Rupp. 



Flowers white or rose-red in colour, homogamous or feebly protogynous, 

 arranged in unibels ; nectar half-concealed, secreted at the base of the ovary. 



1770. L. palustre L. (Warming, Bot. Tids., Kjobenhavn, xv, 1885, PP- 

 39-44 ; Loew, ' Blutenbiol. Floristik,' p. 271 ; Knuth, ' Bloemenbiol. Bijdragen.') — 



