54 ANGIOSPERMAE—DICOTYLEDONES 



ones tetramerous. Kirchner states that the former has ten, while the latter have 

 eight small narrow nectaries at the base of the ovary, which project into gibbosities of 

 the petals that serve as nectar-receptacles. The erect dentated petals are about 

 15 mm. long, and closely apposed laterally, so as to contract the opening of the 

 flower to 4-5 mm. This is almost blocked up by the large capitate stigma, which 

 is 3-3-1 mm. broad. A proboscis at least 10 mm. long is required to reach the 

 nectar. There is a central pit in the stigma, surrounded by a wall of very sticky 

 papillae and the lower side of the stigma is surrounded by whiti.sh hairs which help 

 to prevent self-pollination. The anthers are situated rather below the stigma at the 

 level of these hairs, and dehisce extrorsely. Insect visitors must first touch the stigma 

 with their heads, dusting it with pollen if they have previously visited another flower, 

 and at the same time making their head or proboscis sticky with stigmatic fluid, so 

 that the white pollen against which they at once brush will adhere to them. Crossing 

 is thus ensured, while automatic self-pollination would seem to be excluded. Warns- 

 torf describes the pollen-grains as white in colour, spheroidal, smooth, and about 

 25 /i in diameter. 



Visitors. — I observed the humble-bee Bombus agrorum F. 5, skg. (length of 

 proboscis 10-15 mm.) on Wollin Island. 



LXI. ORDER EPACRIDEAE R. BR. 



Delpino ('Ult. oss.') says that some of the species of the genus Epacris are 

 protogynous. 



534. Richea R. Br. 



1788. R. sprengelioides F. Muell. ( = Cystanthe sprengelioides R. Br.). 

 (Borzi, • Contrib. alia biol. veget.,' II, Ease, i, Palermo, 1^97.) — Borzi sa}s that this 

 species is anemophilous. 



LXII. ORDER DIAPEKSIACEAE LINDL. 



535. Diapensia L. 



1789. D. lapponica L. (^^'arming, ' Besiovningsmaade,' pp. 34-6.) — This 

 species, native to high latitudes, is said by Warming to be feebly protogynous in 

 Greenland. The stigma and anthers are tolerably far apart, so that automatic self- 

 pollination is rendered difficult, but sometimes the anthers dehisce in the bud, so that 

 autogamy can take place when the flower opens. Nectar is abundantly secreted at 

 the base of the ovary, and is completely concealed. 



Lindman states that the flowers are protogynous on the Dovrcfjeld. The 

 stamens are at first curved inwards, but afterwards become erect, though autogamy is 

 excluded, for the flowers always remain erect, and the anthers project beyond the 

 stigma. 



Vanh6ff"en noticed (27. 6. '93) fruiting plants in Greenland (Abromeit, ' Bot. 

 Ergeb. von Drygalski's Gronlandse.xped.,' p. 47). 



Visitors. — Ekstam observed flies in the Swedish Highlands. 



