CYPERACEAE 513 



stage and others in the i (second) stage at the same time ; this brings about dioecism, 

 so that cross-pollination by means of wind can take place very frequently. Besides 

 this, however, small staphylinid beetles, which I frequently found thickly dusted with 

 pollen in the spikelets, seemed to efiect cross-pollination. The pollen-grains are pale- 

 yellowish in colour, irregularly tetrahedral to bluntly-triangulo-pyramidal, about 37-5 

 to 43*7 /A broad and 62-^ fi long. 



In addition to normal flowers with three stigmas, others with two sometimes 

 occur. 



2966. S. Caricis Retz. (=S. compressus Pers.). In this species the pollen- 

 grains are pale-yellowish in colour, rounded tetrahedral, feebly papillose, 37-5 to 44 /t 

 in diameter. 



2967. S. sylvaticus L. This species is strongly protogynous, with persistent 

 stigmas. The stamens do not mature until some days later than the latter. The 

 pollen-grains are yellowish in colour, tetrahedral with small tubercles, about 91 /x in 

 diameter. 



973. Eriophorum L. 



2968. E. polystachion L. This species is protogynous. The flowers are 

 hermaphrodite or purely female ; specimens with only female ones are often found in 

 sheltered stations. The style of the female flower, bearing 3 long stigmatic branches 

 closely beset with papillae, projects far beyond the bracts. The pollen-grains are 

 sulphur-yellow in colour in the mass, tetrahedral, tuberculate, on an average 37-40 fi 

 in diameter (Warnstorf). 



I. M. Normann (Bot. Not., Lund, 1868, p. 13) states that in the north of Norway 

 this species is sometimes hermaphrodite and dioecious. 



2969. E. vaginatum L. Raunkjaer says that this species is sometimes com- 

 pletely gynodioecious. 



974. Kobresia Willd. 



Pax describes the spikes as consisting of some two-flowered spikelets, in which 

 the terminal one is male and the lateral female. 



975. Carex L. 



2970. C. dioica L., and 2971. C. Davalliana Sm. In these species individuals 

 bearing single or more numerous female flowers, at the base or in the middle of the 

 male spikes, are not rare. 



2972. C. baldensis L. The yellowish-white, capitate inflorescences in this 

 species, formed by the grouping together of the spikelets, are extraordinarily con- 

 spicuous, and undoubtedly attract insects, which effect crossing. At Riva, Appel 

 observed gnats, and a few small beetles. The size of the inflorescence varies greatly, 

 and its conspicuousness is affected by the presence or absence of the largest part of 

 last year's dark-green foliage during anthesis. Appel observed that these conditions 

 varied according to the altitude in the neighbourhood of Lake Garda. 



DAVIS. Ill L 1 



