APPENDIX A 



617 



succession, so that it can be obtained in the flowering state throughout the 

 summer. The flowers can be made to open at any time by keeping them warm, 

 and in water. 



The inflorescence is borne on a long stalk, above the uppermost foliage 

 leaf, which has a split sheath, ligule, and lamina. It is a compact, com- 

 pound spike, composed of spikelets placed edgewise, alternately on its two 

 sides, with one terminal. Each lateral spikelet, which consists of an axis 

 bearing flowers alternately in two rows, arises in the axil of a bract, or outer 

 glume (Fig. 464, 1.). In most Grasses there is a second, or inner glume, on 

 the side opposite to the outer ; but this, being unnecessary for protection in 

 the dense inflorescence of the Rye-Grass, is not present, except in the 

 terminal spikelet. Each flower is ensheathed in two further bracts or 



paleae : the lower and outer is 

 anterior, the upper and inner is 

 posterior, and the flower itself 

 lies between them. At flower- 

 ing they gape widely apart, so 

 as to expose the parts of the 

 flower (I). If a flower be found 

 in this condition, or if the lower 

 palea be forced back, the flower, 

 as seen from the anterior side, 

 will show the following parts : 

 (i) Two lodicules, which are 

 minute, colourless, hypogynous 

 scales, right and left of the 

 median plane (/). It is by their 

 swelling that the paleae are 

 forced apart at the time of 

 flowering. 



(ii) Three stamens (st), hypo- 





Fig. 465. 



gynous, free, with long flexible 



Part of a median longitudinal section of a grain of 

 Wheat, showing embryo and scutellum (sc). i>s = vase, 

 bundle of scutellum; ce — its columnar epithelium; 

 i' = ligule ; c— sheathing part of cotyledon ; pv = \ege- 

 tative cone of stem; /i£ = hypocotyl ; / = epiblast; 

 r = radicle; cl = root sheath ; m — micropyle ; /> = funi- 

 culus; u/> = vascular bundle of funiculus; /=lateral 

 wall of groove ; cp=pericarp. ( x 14.) (After Stras- 

 burger.) 



filaments, and versatile anthers, 

 bearing powdery pollen. One 

 stamen is median and anterior, 

 the two others obliquely pos- 

 terior. 



(iii) The gynoecium, lying 

 centrally, consists of a pear- 

 shaped superior ovary, grooved on the posterior side, and bears distally, right 

 and left, two feathery stigmas. Dissection shows a single ovule in the ovary. 

 The number of such flowers in each spikelet varies : 8 to 10 are common 

 numbers in the Rye-Grass, and they open at intervals in acropetal succession. 

 The flower may be held to be of Liliifloral type, reduced in relation to wind- 

 pollination. The perianth is represented by the two lodicules, corresponding 

 to the oblique anterior segments of the inner series, which being of use in 

 separating the paleae at flowering have survived. The stamens correspond in 

 position to the outer whorl of the Liliiflorae, while the gynoecium is held to 

 consist of a single carpel, corresponding to the anterior carpel of the Liliiflorae. 



