List of monocotyledons of Montana

Monocotyledon species found in Montana number at least 615. The Montana Natural Heritage Program has identified a number of monocot species as "Species of Concern".
Monocotyledons are one of two major groups of flowering plants (or angiosperms) that are traditionally recognized, the other being dicotyledons, or dicots. Monocot seedlings typically have one cotyledon (seed-leaf), in contrast to the two cotyledons typical of dicots. Monocots have been recognized at various taxonomic ranks, and under various names (see below). The APG II system recognises a clade called "monocots" but does not assign it to a taxonomic rank.
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 more than 20,000 species. In agriculture the majority of the biomass produced comes from monocots. The true grasses, family Poaceae (Gramineae), are the most economically important family in this group. These include all the true grains (rice, wheat, maize, etc.), the pasture grasses, sugar cane, and the bamboos. True grasses have evolved to become highly specialised 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.
Arrow-grass family.
Order: Najadales, family: Juncaginaceae 
Arum family.
Order: Arales, family: Araceae 
Bur-reeds.
Order: Typhales, family: Sparganiaceae 
Cattails.
Order: Typhales, family: Typhaceae 
Ditch-grass family.
Order: Najadales, family: Ruppiaceae 
Duckweeds.
Order: Arales, family: Lemnaceae 
Flowering-rush family.
Order: Alismatales, family: Butomaceae 
Grasses.
Order: Cyperales, family: Poaceae 
Greenbriars.
Order: Liliales, family: Smilacaceae 
Horned pondweeds.
Order: Najadales, family: Zannichelliaceae 
Irises.
Order: Liliales, family: Iridaceae 
Lilies.
Order: Liliales, family: Liliaceae 
Orchids.
Order: Orchidales, family: Orchidaceae 
Pod-grasses.
Order: Najadales, family: Scheuchzeriaceae 
Pondweeds.
Order: Najadales, family: Potamogetonaceae 
Rushes.
Order: Juncales, family: Juncaceae 
Sedges.
Order: Cyperales, family: Cyperaceae
Spiderwort family.
Order: Commelinales, family: Commelinaceae 
Sweetflag / calamus family.
Order: Arales, family: Acoraceae 
Water-hyacinth family.
Order: Liliales, family: Pontederiaceae 
Water-nymph family.
Order: Najadales, family: Najadaceae 
Water-plantains.
Order: Alismatales, family: Alismataceae 
Waterweeds.
Order: Hydrocharitales, family: Hydrocharitaceae 
Yuccas / agaves.
Order: Liliales, family: Agavaceae 