No matter how much you think you know about plants, there are still plenty of surprises that await.  With nearly 400,000 plant species identified world wide, it is little wonder that every time you step into a nursery, there is something new to discover.

Even within a single plant genus, there may be so many species that you would need a lifetime to explore them all.  Take irises, for example.  There are 300 species of iris yet only two of them — bearded and Dutch iris — are familiar to most gardeners.  Many more of them should be.

Just the other day, I was astonished to see a bearded iris blooming close to the ground.  Typically, bearded irises are borne on flower stalks around two feet tall and some, such as Siberian irises, may be up to four feet tall.   But the flower stalk on this particular iris could not have been more than six inches in height and the falls (downward oriented petals) nearly touched the earth.

I learned that this low grower is known as a miniature dwarf bearded iris.  Moreover, there are a number of diminutive irises worthy of planting.  The most famous goes simply by the name of dwarf iris (Iris reticulata).  Flowers are dainty at a height of 4-6 inches, foliage is grass-like, and a group of them clustered together make an excellent choice for container planting.  Due to their small size, when a mass of their flowers bloom all at once in crowded container confinement, they present an eye-popping floriferous accent guaranteed to take your breath away.  There is also the pygmy iris (Iris pumila), a highly hybridized species that grows from bulbs to a height of 4-8 inches.  Flowers have features of both bearded and Dutch irises.  You will never see these irises in a nursery but they are readily available through Internet vendors.

Pacific Coast irises, many of which are also hybridized, may range from 6-24 inches in height although it is those of shorter stature that are generally encountered in local gardens and nurseries.

You never forget your first encounter with a memorable plant.  I first saw Pacific Coast irises growing on the shady edge of a garden where sprinklers did not reach and so the soil in that spot was hard and dry.  I initially had no idea as to what this plant might be.  It was the middle of summer and its leaves lay almost flat on the ground.  But then, the following spring, all of a sudden, I saw flower buds open up into silky white petals with golden throats, yet another testimony to the resiliency of plants in general, and to those that grow from bulbs or rhizomes in particular.

Are there any unusual irises that you grow and would like to share with readers of this column?  If so, please send along your iris experiences to the email address given below.

In response to recent columns on fragrant and tactile plants I received the following email from Terry Barber.  “I am a garden docent at Rancho Los Cerritos in Long Beach,” Barber wrote.  “One of the best aspects of my garden tour is letting everyone touch and smell the plants. We also have four herb gardens for 4th graders on my morning tours. We have the children touch the plants and then smell their fingers. We teach the children about how Native Americans and pioneers used our local plants.

My favorite plants for smell and touch are Santolina, French lavender (Lavandula dentata), rosemary, pineapple sage (Salvia elegans), Cleveland sage (Salvia clevelandii), peppermint geranium (Pelargonium tomentosum), fennel (Foeniculum vulgare), cassia and Heliotrope.”

With the above selections, you have provided opportunities to introduce kids to some of the more exotic garden fragrances and textures.  The foliage of pineapple sage really does smell like pineapples and its long blooming sprays of scarlet flowers are an added bonus.  The large leaves of peppermint geranium are pure velvet to the touch and their smell is pure peppermint. Peppermint geranium is unjustifiably overlooked as a ground cover.  It spreads rapidly and needs little water to flourish.  On the coast it handles full sun but will need afternoon sun protection inland.

I do not know which cassia is growing in Rancho Los Cerritos but popcorn cassia (Senna didymobotrya) has a foliar fragrance, as its name denotes, that is truly unique in addition to large, tightly bunched black buds that open to reveal deep yellow flowers.  Just make sure that the kids smell the leaves, which are toxic, but refrain from chewing on them.

Tip of the Week:  People who complain about the work involved in gardening should plant nothing but species that grow from bulbs, rhizomes, corms, and tubers, since they live for decades and spread or naturalize with a clumping growth habit.  In our climate, not all such plants — generically classified as herbaceous perennials — are suitable, but the following have proven themselves to survive and perform consistently for years without much fuss, other than removal of dead leaves: lily of the Nile (Agapanthus), daylily (Hemerocallis), canna lily (Canna), calla lily (Zantedeschia), daffodil and Narcissus, Watsonia, bear’s breech (Acanthus mollis), Chasmanthe, Crocosmia, Nerine, bird of paradise (Strelitzia) and, of course, irises.  Are there any other herbaceous perennials that you would recommend?  All of the above may be planted in full sun along the coast and in full to half day sun inland, depending on the species, with the exception of bear’s breech, which prefers a mostly shady placement.  Note that the flowers of all of the above stand up well in a vase, except for canna lilies.  Canna leaves, however, are durable and sometimes colorfully striped, adding interest as background or filler in flower arrangements.