MUCRO: A short, sharp spur as on a tip of a leaf.
MUCRONATE: Terminated by a sharp tip.
MUCRONULATE: Having a very small mucro.
MULCH: Any substance, usually a layer of organic material, applied to the soil over or around a plant to conserve moisture, protect the roots from frost, reduce the growth of weeds, and enrich the soil (i.e. bark chips, rotted manure, garden compost, gravel, black plastic).
MULCHING PAPER: A biodegradable sheet made of peat that is used to reduce water evaporation and keep weeds down.
MULE: A plant hybrid that is self-sterile and usually cross-sterile due to infertile pollen or undeveloped pistils.
MULL: A humus-rich layer of forested soils consisting of mixed organic and mineral matter.
MULTICARPELLATE: Having a compound pistil or ovary formed by the joining of several carpels.
MULTIPLE FRUIT: A fruit such as the pineapple, which is actually the fruits of several flowers that have formed in a single cluster.
MURIATE OF POTASH: This is a slow-acting fertilizer that adds oxide of potassium to the soil. Same as potassium chloride.
MURICATE: Having a rough surface due to the presence of many tiny sharp points.
MUSCIFORM: Relating to or resembling moss.
MUTATION: An alteration in genetic material caused by an actual physical change within the genes of a cell. When such changes occur in the germ cells, they are able to be passed on to the offspring as inherited traits, producing such effects as a leaf shape or flower color different from that of the parent.