Lecture 2a: Plant Structure: roots, shoots (audio)

As in most the lectures of this course, here is the usual mention that these lectures on plant structure may seem like a lot of terms, but only are the tip of the iceberg of botanical terms relating to plants. Check in botany texts, even in depth gardening texts for these. But what follows under roots, shoots, leaves and flowers are the most commonly encountered in horticulture and gardening, beginning with root types and terms. To help visualize each set of terms, click on the page for drawings. You might find it helpful to listen along to the lecture while looking at these drawings, or if not listening, to print these out to refer to while reading the text.

Roots (root drawings)

fibrous: many small roots, often near the surface

tap: one to several main thick roots, deep, making plants hard to transplant, such as Baby's Breath (Gypsophila)

rhizome: a creeping and thickened stem, usually partly or totally underground, with shoots from the top and roots from the bottom, such as Bearded Iris

bulbs: short underground stems, with the growing point surrounded by fleshy scales (modified leaves) that store food and produce baby bulbs called bulblets, as with narcissus or daffodils.

corms: swollen underground stems, broader than high, which produce offshoots called cormels, as with crocus or gladiolus.

tubers: thickened underground stems which don't creep, as with dahlias

Shoots

There are two main terms to keep in mind with shoots.

node: the place where the leaf joins the stem

internode: the part of the stem between the nodes