Qualiative and quantitative determinations were made of the reserve carbohydrates and the component sugars of hemicellulosic substances in the vegetative parts of various species of grasses and legumes. Plant materials employed in this study were leaf-sheathes and stems in heading stage of twenty-five species of grasses and were leaves and stems in the flowering stage of five species of legumes. As reserve carbohydrates in the aerial parts, most species of the grasses accumulated either fructosan or starch usually together with sucrose, and may be able to be classified into three groups by difference in the type and relative proportion of individual carbohydrates as follows. Group 1. Accumulating fructosan, together with sucrose but no starch Group 2. Accumulating starch with sucrose but no fructosan Group 3. Accumulating sucrose but no fructosan The fructosan-containing grasses in Group 1, the sixteen species of the Gramineae, were essentially species of "Northern type" native to cool, temperate climates, and the other eight grasses in Group 2 and 3, which accumulated either sucrose and starch or sucrose only, were species of "Southern type", being adapted to warm regions. According to the HUBBERD system of plant classification, grasses in Group 1 and Group 3 taxonomically belong to subfam. Festucoidea and subfam. Panicoidea respectively, and members in Group 2 belong to three subfamilies of Eragrostoidea, Panicoidea and Banbsoidea. Therefore, there were the two types of reserve carbohydrate in members of subfam. Panicoidea. of seventeen grasses classified to subfam. Festucoidea, red top, bent grass and timothy, members of the Agrostideae, accumulated highest fructosan in relative proportion of individual reserve carbohydrates, and four grasses in the Bromeae and in the Hordeeae contained more plentiful sucrose than members in other tribes of the same subfamily, Festucoidea, although all of them contained fructosan together with sucrose as reserve carbohydrates. The leaf-sheath and stem of most grasses were the same as underground parts with respect to the type of reserve carbohydrate compositions, but were not always similar to the leaf-blades or seeds, which contained higher amounts of starch and no fructosan in most species of the Gramineae. Hemicelluloses of some grasses and legumes were constituted in descending order of aboundance by xylose, glucose or arabinose and galactose, and rhamnose in trace. In comparisons among species of grasses, differences were noted in glucose and in corresponding xylose contents. In hemicelluloses of Southern grasses, glucose was present more plentifully while xylose correspondingly was less as compared with those of Northern grasses or subfam. Festucoidea. When the type and individual proportions of carbohydrate constituents in the aerial parts are considered in relation of taxonomic classification of the Gramineae, it is seen that qualitative and quantitative differences exist respectively with respect to the reserve carbohydrates and with respect to the component sugars of hemicellulosic substances among subfamilies of the Gramineae ; that members of some tribes were quantitatively distinct from members of other tribes in the same subfamily, Festucoidea, in amounts of reserve carbohydrates, such as fructosan and sucrose. Five members of legumes examined contained principally starch with sucrose in aerial parts as reserve carbohydrates and appeared to be distinct from members of the Gramineae in containing more galactose and rhamnose as the component sugars of hemicellulose.
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