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Lilioid monocots or lilioids is an informal name used for a grade of five monocot orders (Petrosaviales, Dioscoreales, Pandanales, Liliales and Asparagales) in which the majority of species have flowers with relatively large, coloured tepals, broadly similar to those of lilies. Another name for this group is petaloid monocots, because the flowers have tepals which all resemble petals. In older classification systems, still found in many books and other sources, many of the species in this group of plants were put into a very broadly defined family Liliaceae (lily family). Within the monocots they were distinguished from the Glumaceae. ==Flowers== }} }} }} }} }} }} The diagram shows a cladogram of the monocots in which the bracket marks the lilioid monocots, namely the orders Petrosaviales, Dioscoreales, Pandanales, Liliales and Asparagales. The lilioid monocots all have flowers which can be considered to have been derived from a lily-like flower with six relatively similar tepals, six stamens, and a superior ovary composed of three carpels, with nectaries at the base. This pattern is primitive (plesiomorphic) for the lilioid monocots. Various trends are apparent among the lilioids, notably a change to an inferior ovary and a reduction of the number of stamens to three. In some groups (such as the genus ''Trillium'' in the Liliaceae), the tepals have become clearly differentiated, so that the flower has three coloured petals and three smaller green sepals. Almost all lilioid monocots retain at least three petal-like tepals. Since some commelinids (e.g. ''Tradescantia'') do have petaloid flowers, the term 'lilioid' is a more accurate one for the group which excludes them. In John Lindley's system (1830) they were described as the tribe Petaloideae. In the orders that branched off before the lilioid monocots, the Acorales and Alismatales, flowers differ in several ways. In some cases, like ''Acorus'', they have become insignificant. In others, like ''Butomus'', they have six coloured tepals, and so could be called 'petaloid', but stamens and carpels are more numerous than in the lilioid monocots. The later evolved commelinids have various kinds of flower, few of which are 'lily-like'. In the order Poales, comprising grasses, rushes and sedges, flowers are either petal-less or have small, unshowy petals. Many Zingiberales species have brightly coloured and very showy flowers. However, their apparent structure is misleading. For example, the six tepals of cannas are small and hidden under expanded and brightly coloured stamens or staminodes which look like petals, but are not. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lilioid monocot」の詳細全文を読む スポンサード リンク
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