Scientific name: LiliopsidaEnglish name: MonocotsVietnamese name: Một lá mầmOther name: Monocotyledoneae
Monocotyledons or monocots are one of two major groups of flowering plants (angiosperms) that are traditionally recognized, Dicotyledons or dicots being the other. Monocots have been recognized at various taxonomic ranks, and under various names (see below). The APG II system recognizes a clade called "monocots" but does not assign it to a taxonomic rank. Monocots comprise the majority of agricultural plants in terms of biomass produced. There are between 50,000 and 60,000 species within this group; according to IUCN there are 59,300 species. The largest family in this group (and in the flowering plants as a whole) by number of species are the orchids (family Orchidaceae), with about twenty thousand species. The economically most important family in this group (and in the flowering plants) are the grasses, family Poaceae (Gramineae). These include all the true grains (rice, wheat, maize, etc.), the pasture grasses and the bamboos. This family of the true grasses have evolved in another direction, becoming highly specialized for wind pollination. Grasses produce much smaller flowers, which are gathered in highly visible plumes (inflorescences). Other economically important monocot families are the palm family (Arecaceae), banana family (Musaceae), ginger family (Zingiberaceae) and the onion family Alliaceae, which includes such ubiquitously used vegetables as onions and garlic. Many plants cultivated for their blooms are also from the monocot group, notably lilies, daffodils, irises, amaryllis, orchids, cannas, bluebells and tulips. The name monocotyledons is derived from the traditional botanical name Monocotyledones, which derives from the fact that most members of this group have one cotyledon, or embryonic leaf, in their seeds. This as opposed to the traditional Dicotyledones, which typically have two cotyledons. From a diagnostic point of view the number of cotyledons is neither a particularly handy (as they are only present for a very short period in a plant's life), nor totally reliable character. Nevertheless, monocots are a distinctive group. One of the most noticeable traits is that a monocot's flower is trimerous, with the flower parts in threes or in multiples of three. For example, a monocotyledon's flower typically has three, six, or nine petals. Many monocots also have leaves with parallel veins.