Botany for Gardeners

Connie Holland
Adams County Master Gardener

This article is the first in a series about the study of plants, knows as botany, for gardeners. It starts with a story about a wonderful acquaintance (whose second ever quilt won a $10,000 prize, but that is another story). As a toddler-aged child in war torn Germany, my friend often played in the gardens of a convent while her mother was meeting with nuns who sewed clothing for the family. One nun in particular, Sister Maria, would catch her in the garden pulling up seedling plants, peering at the broken stems. When the nun asked what she was doing, the child answered, "I am looking for the colors".

Her explanation is she thought the flower colors must be locked inside the stems, waiting to come out. Sister Maria was an artist who designed charming postcards popular throughout Germany. She used the child as a model depicting her picking and dismantling the flowers on one of her postcards. Sister Maria actually was Sister Maria Hummel whose designs became the popular ceramic Hummel figures of today. I have seen the postcard of my friend as the child and the actual Hummel figurine based on her.

The reason for this story is that I also find the cells inside in a plant to be amazing wonders of nature. As I look at my garden this time of year, longing for its wonderful colors where I see only bare brown perennial beds with little showing above ground, I think to myself, how do the plants do it? How do perennials always come up on schedule and bloom with such reliability? In the spring, when planting my tiny watermelon seeds, I think of the dozen-plus huge watermelons I will get from each tiny seed and wonder just how does it all happen?

Did you know that plants have specialized cells devoted to unique horizontal and vertical development from their seeds, or devoted to branch growth and maturity, even devoted to repair when damaged? A basic understanding of botany can be very helpful to gardeners. It helps explain why our plants do, or even more importantly, donít do as well as we would like in our gardens.

There are some 400,000 thousand recognizable species of plants. The two groups recognized most often by gardeners are flowering plants called angiosperms that develop from seeds inside some "container" like a seedpod, and plants called gymnosperms that develop from seeds in "open" cones such as a pine tree.

Seeds can survive conditions such as freezing, years of storage, and drought that would kill their parent. Inside a seed, waiting to be born, or germinate, is a plant embryo. Seed germination is stimulated by changes in the seedís environment, time, temperature, moisture level, direct sunlight exposure, breaking of a seedís coating called scarification by scratching or even fire, or by prolonged low temperature exposure called stratification.

Once born, special cells called apical meristems respond to gravity and begin forming downward root(s) (think of a tap root). Lateral meristems form branched roots to the sides. If the apical meristem cells at the end of the bottom root(s) are severely damaged or cut off, then chances are the roots will no longer develop. Now you may better understand why plants with a tap root are harder to transplant. Out of sight below ground, roots anchor a plant in the soil, absorb water and minerals, and store food. A carrot is an excellent example of a tap root food storage system. When perennials die back in winter or deciduous trees lose their leaves, it is the food stored in their roots that enables them tor return in the spring.

Roots probing the soil for water and minerals have protective root cap cells. These cells enable roots to work their way through the soil, around large objects, even severing objects in their way. Sewer pipes and large rocks are often seen penetrated by roots. Who would think such cells could be so powerful?

A seedís first developing structures above ground are called cotyledons, embryonic leaves that come from inside the seed and store enough food to nourish the first "true" leaves on the plant. (See accompanying drawing of a seedling). As a seedling develops, they shrink and eventually fall off having served their purpose. The size of these cotyledons determines just how deeply a seed can be planted, the larger they are, the deeper the seed can be planted. Embryos of very tiny seeds such as carrots, planted too deeply, have no chance of surviving to reach the surface, since their cotyledons do not have enough food to last the trip!

Plants called a monocot have one cotyledon, such as grasses, grains, lilies, irises or orchids. Or they are a called dicot having two cotyledons as in roses, asters or trees. Germination ends when the new plant seedling emerges from the soil. A future article will explain the wonders of more specialized cells that control a plantís development, even recovery from pruning and what causes branching.

Latin for Gardeners: a Brief Pronunciation Guide

A Primer on Plant Nomenclature

Read other articles by Connie Holland