Look at the hostas in your garden and guess whether they are more closely related to field corn (Zea mays) and Kentucky bluegrass (Poa) or to plants like Coralbells (Heuchera) and rhubarb (Rheum). With their often very large, roundish leaves, most people would probably say that hostas are more closely related to rhubarb than to grass. Unfortunately, they would be wrong.

All vascular plants can be divided into two broad categories: Monocotyledons a.k.a. monocots and Dicotyledons a.k.a. dicots. Hostas are monocotyledons. This group includes all the grasses but other plants that look quite different, such as hostas, are also monocots.

The following chart compares the major traits of the two groups:

One key point between the two groups of plants concerns the location of buds which can lead to new growth. In the monocots like hostas, if you cut off the leaf blade, a new one will NOT form on the remaining stalk. The leaf stem i.e. petiole, has to be cut down to ground level to trigger the formation of a new bud on the hosta's underground crown which may then send up a new leaf.

On dicots such as petunias, if you cut off a leaf, that may trigger a new bud located on the stem to open and form a new leaf. This is the reason for "pinching" such plants to form a thicker, denser canopy of foliage. Pruning dicot trees will cause nearby buds on the stem to break and produce new twigs and stems.

Since hostas are monocots, they bear their plant parts in groups of three. The showy part of the flower which would normally be called petals are actually tepals on hostas. Tepal is the term for the combination of the sepals (the green modified leaves that cover the petals while in bud) and the actual petals of the flower. There are normally 6 tepals in a hosta flower along with six stamens (male parts) and three carpels or ovaries in the pistil (female parts).