A Glimpse of Nature -- A Monocot

The Missouri Botanical Garden describes the daylily as “A tough plant that is tolerant of poor soil, summer heat and humidity.”  Our recent high temperatures and frequent showers may be challenging to humans, but the daylilies at the Ames Free Library have bloomed with exuberance.  Each July, they greet visitors entering the property.

Originally from Asia, these perennials have traveled the world, carried by people who valued the plant’s edible roots and blossoms, its medicinal properties, and its beauty.  Daylilies have now naturalized across much of the United States, thriving in gardens, forest edges, and floodplains.  Gardeners appreciate the daylily’s adaptability, hardiness, and ability to spread.  Given time, the plant will colonize a bare spot, but the process can be accelerated by dividing the clumps into new plants.  Beginning gardeners can easily grow daylilies, and there are many colors and shapes from which to choose.  Indeed, the American Daylily Society informs us, “As of May 2018, there are nearly 89,000 registered cultivars!” Some specialists develop collections of 100 or more cultivars within their display gardens.

Let’s take a closer look at one plant.

Each individual has a clump of long, grass-like leaves at its base (basal leaves.)  Also arising from the base is a tall “scape”, that is, a leafless flower stalk, which is topped by a cluster of bell-shaped flowers, often in shades of red, orange, or yellow.  One flower per scape (or branch of a large scape) blooms each day, hence the plant’s common name.  As Wikipedia’s entry states, “The flowers of most species open in early morning and wither during the following night. . .”  It’s best to plant daylilies in groups because their flowers open sequentially for a few weeks.

The flower itself has three petals and three sepals of the same color that are fused.  When the petals and sepals look alike, as in this case, they are called “tepals.”  It also has six, pollen-bearing stamens and a three-lobed stigma.

A closer look at a daylily leaf reveals parallel veins just like those of a grass . . . or an orchid, a palm, an iris, etc.  These plants, and many more that share some traits with the daylily, belong to a major plant group called the monocotyledons, or monocots for short.

The monocots are a subset of flowering plants with a common evolutionary history.

They take their name from a feature that, unfortunately, we cannot see in the above photos.  Before they germinate, their seeds contain only one embryonic leaf.  In contrast, dicots rely on a pair of embryonic leaves to make their start in life.  If you’ve ever raised vegetables or seeded a lawn, compare the grass or corn seedlings with those of string beans.

My photos display two key characteristics of monocots:  the parallel veins in their leaves and the flower parts in multiples of three.  When the library’s daylilies complete their bloom, the ovaries of successfully pollinated flowers will develop into seed capsules.  Those capsules will contain three chambers.

Monocots display other distinguishing qualities.  For example, they usually have fibrous roots rather than a main tap root.  Their vascular system and growth process also differ from those of dicots, and so does their pollen.  DNA research during the 1990s showed that the “defining feature” separating the two groups was the number of pores on each pollen grain.  This chart from The Seed Site nicely summarizes the differences.

It’s impractical for most of us to examine the details of pollen grains, though don’t let me deter you!  And, like many systems of classification, this one is in flux and not cut-and-dry.  All the same, it can be very helpful and fascinating to see patterns among the plants in your life.  Next time, we’ll consider a few more monocots.

‘Til then, enjoy the daylilies while they bloom. 

Many thanks to Gloria Freitas-Steidinger for creating the library’s daylily bed.

 

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