5H 



ANGIOSPERMAEMONOCOTYLEDONES 



2973. C. paradoxa Willd. This species is sometimes purely male; sue 

 stocks, since their spikelets in later stages are devoid of fruits, have not infrequentW 

 occasioned crosses with the hybrids of C. paradoxa Willd., C. teretiuscula Good., anj 

 C. paradoxa Willd, or C. paniculata L. Appel says that large sods are often founc 

 of which the inner spikelets are normal composed, but surrounded by a belt of 

 stems, so that the female flowers are pollinated in whatever direction the wind may 1 



Warnstorf describes the pollen-grains as pale-yellowsh-white in colour, tetra-j 

 hedral, tuberculate, on an average from 37 /x in diameter. 



2974. C. Schreberi Schrank (= C. praecox Sc/treb.). Warnstorf descril 

 the pollen-grains in this species as yellowish in colour, spheroidal-tetrahedral, closelj 

 beset with small tubercles, about 30 /x in diameter. 



2975. C. leporina L. Appel not infrequently observed pollen-collecting 

 insects, especially flies, on the spikelets of this species, which indicates the possibilit 

 of entomophily. The varieties argyroglochin Hornem., with its straw-yellow, and 

 atrofusca Christ, with its dark-brown, almost blackish spikes, may also be o| 

 ecological significance. 



2976. C. vulgaris Fries (= C. Goodenowii /. Gay), and 2977. C. strict 

 Good. In these species purely male stems occur not infrequently, or spikelets wit 

 female flowers becoming male at the tip. 



The pollen-grains are pale-yellow in colour, tetrahedral, with rounded comer 

 delicately tuberculate, from 37-43 /t in diameter. (Loew, 'Bliitenbiol. Floristil 

 P- 364.) 



2978. C. praecox Jacq. (= C. verna Vill^. This species, besides C. glauc 

 Scop., is probably one of those in which variations in the position of the spikelet 

 most frequently occur. From the variety gynobasts Spenn., which bears a 

 spikelet on a long, slender stalk, there are all transitions to the type in which or 

 terminal male spikelet is present with one to three female ones close below it. 



The pollen-grains are sulphur-yellow in colour, markedly conical to pear-shaj 

 tuberculate, about 37 /* long and 30 /n broad. 



2979. C. montana L. In addition to the most usual form of this species witi 

 red-brown spikelets, one with straw-yellow male ones is also frequently found. 



2980. C. digitata L. The pollen-grains in this species are sulphur-yellow 

 colour, tetrahedral, tuberculate, 30-7 fi in diameter (Warnstorf). 



2981. C. glauca Murr. This is one of the most variable German species. 

 Besides the normal female flowers with three stigmas, others with two occur fairly 

 frequently. Appel says that the following forms are also found : 



(i) A single terminal male or female spikelet; 



{2) A basal long-stalked female spikelet, otherwise normal ; 



(3) All female spikelets with short stalks and distributed over the upper two-thir 

 of the stem ; 



(4) Female spikelets with long stalks, hanging over when the fruit ripens, 

 inserted more or less widely apart ; 



(5) Female spikes are either all, or the terminal one only, male at the tip ; 



