A. caryophyllea, L.
xx Paleæ almost imperceptibly bidentate: awn not much longer than palea. About 12-18 inches high: leaves inrolled.
A. flexuosa, L.
Other species of Aira, with more condensed inflorescences, are dealt with on p. [112]. Agrostis is distinguished by the leaves and one-flowered spikelets (see p. [104]). Poa and Catabrosa have no awns.
CHAPTER VIII.
THE FRUIT AND SEED.
The stigma of an ordinary grass consists of two divaricating plume-like structures composed of thin-walled cells. When the paleæ open these stigmatic plumes protrude, one on either side, and readily catch pollen shed from the dangling stamens and carried by the wind, and since the pollen of the same flower is usually shed at a time when the stigmas of many neighbouring plants are mature, there is every opportunity for cross-fertilisation. (Fig. [33].)
In some cases, however, e.g. Anthoxanthum, Alopecurus, the flowers are proterogynous, the stigmatic plumes being ready for pollination some time before the pollen is shed from the anthers of the same flower; whereas in most of our grasses the pollen begins to scatter before the stigmas
