Plant Science Facts: Leaves, Roots, Flowers

ivy aerial root
Facts true for most of the garden plants we grow. Mouse over confusing words for definition/explanation.


Leaves are how most plants get their sustenance. Plants live and breathe through their leaves. In this process (inverse to ours), we humans benefit. The plant world needs carbon dioxide, which we exhale, and we need the oxygen they send into the atmosphere. This is why rain forests are so necessary to our atmosphere.

It is also why it is healthy to have houseplants inside our stuffy houses. [ 1 ]

Houseplants Best for Humans

Plants recommended:

  • Corn plant (Dracaena Massangeana),
  • English Ivy (Hedera helix),
  • Gerbera daisies (Gerbera jamesonii),
  • Golden pothos (Epipremnum aureum),
  • Madagascar Dragon Tree (Dracaena),
  • Peace Lily (Spathiphyllum),
  • Rubber plant (Ficus elastica),
  • Spider plant (Chlorophytum comosum),
  • Sword or Boston fern (Nephrolepis exaltata),
  • Weeping fig (Ficus benjamina)

Parts of a Plant

Leaves Can Breathe

Leaf Transpiration, Leaf Respiration, and Stomata

Gardening When It Counts: Growing Food in Hard Times (Mother Earth News Wiser Living Series)


The tubes that conduct water and food up from roots to the leaves are called the xylem.


Stomata are the pores of the leaves. Some of the transported liquid from the roots to the rest of the plant evaporates through those pores; we call this “transpiration”. The loss of water through the leaves into the air.
Plants can have qualities that reduce transpiration to increase their survival in drought or desert climates: hairy leaves, or succulent leaves, such as the sedums.

For gardening practices using this fact for water conservation, you might want to spend some time reading this handy online resource on “water wise” gardening, by Steve Solomon.

Leaves Can EatStomata absorb nutrients and you can use foliar feeding fertilizer during the growing season. The Stomata will open and close in response to daylight and temperature. Foliar feeding is best in the early morning, evening, and when the temps are between 65° and 85°. this method is most helpful to give an early boost, or when plants seem under stress. You can make your own manure and compost teas for foliar feeding.

Make Manure Tea

Use a burlap bag to hold well-aged manure. Suspend in water in a 5 gallon bucket. (Use a ration of 5 parts water to 1 part manure). Compost tea is made the same way but with compost from your pile.

Parts of a Plant Links

Leaf surfaces, illustration.
Read more about plant parts


What is BRIXBRIX is the measure of the percent of solids in a given weight of plant juice (info,here)? How do I get more? Increasing organic matter, mulching, and foliar feeding all increase brixmeasure of flavor and sweetness in foods.

Get Your Own Sugar Refractometer (FREE Shipping).

How do I take a brix reading? Check out this video:

Roots Can Drink, But Don’t Drown Them


All that leafy greenness is nothing without the roots. Roots grow first from the little seeds we plant, and then the tiny stems and leaves climb up into the light. The roots gets the moisture and the nutrients that engine the growth of the plant.

There are types of roots, and when we gardeners speak of bulbs and tubers… we are talking about the food storage systems, but there are other things to know about roots. Lots of things.

prairie plant roots

Plant root parts


Facts About Roots

Roots need moisture to grow
Roots follow a downward path, called gravitropismroots grow in the direction of gravitational pull
More about Gravitropism.

Growing Tips, Literally

The apical meristem cellsembryonic tissue are where all the new growth takes place, and they are present at all places of new growth: buds, stems, and roots.

Root hairs are short lived parts of the root, and absorb most of the water and nutrients for the plant. The practice of “root pruning” is to encourage more of these roots. Roots grow into different types of structures and you can see some plants with strong tap roots, some with storage in their roots, some with fine root systems. As a gardener, you may not have to know all the scientific names of these structures, but you will run across different ways that plants are propagated according to their roots. Peonies have little “eyes” which are the growing points for the plant. Plant with strong taproots are notoriously hard to transplant (not impossible, though).

Some plants propagate through their roots, and are commonly described as having “running roots” (called stolonstravel laterally and root at the joints for new plants and rhizomestravel underground laterally and send up new shoots.). You can see the picture in your mind, and sometimes it is a race to control them- one the gardener will often lose.

There are also roots which propagate from cut pieces, and some roots send up new plants (suckers). Many weeds have these aggressive type of roots. There are some common garden plants that do, as well.

Plenty of today’s garden controversy surrounds the choice of whether to plant these invasive plants in our gardens, particularly if the plant was introduced into the environment instead of native to it.


Illustrations of the Flower Parts

Flowers are the reproductive parts of plants, and what most gardeners consider the big show. It isn’t until later, usually, that we settle down and realize that the garden is much more than just the flowers. But for pollinators, like bees, flies, and hummingbirds, the flowers are truly the main production.

Diagram of Flower Parts

flower parts

flower parts

  • The Pedicel is the base.
  • The Sepals cover the bud and remain at the base, and these make the Calyx.
  • Corolla consists of the petals above the Calyx, together which are called the Perianth.
  • The Stamens and Anthers are the male parts of the flower called the Androecium.
  • The Pistil has the Carpel with the Style which connects the Ovary with the Stigma.

Look up any of these terms in this Glossary.

The Manitoba Regional Lilies Page

Useful page which illustrates the terms in the lily group:
PISTIL . . . The central female part of the flower, composed of OVARY, STYLE and STIGMA.

OVARY . . . Thick part of the PISTIL where it joins the stem. It contains OVULES which, when fertilized, become the seed. A single ovary may contain as many as 2,000 ovules.

STYLE . . . The long slender part of the PISTIL . . . Bears the STIGMA on its tip, and joins the OVARY at the other end.

STIGMA . . .The “knob” on the end of the PISTIL which receives the POLLEN. A sticky substance called STIGMATIC FLUID bathes the stigma when it is “ready,” holds the pollen and stimulates it to germinate.

FILAMENT . . . Stalk of the STAMEN which supports the POLLEN‑bearing ANTHER at its tip.

NECTARY (or NECTARY‑FURROW) . . . Nectar producing groove at base of a PERIANTH SEGMENT . . . often in a contrasting color to form a pronounced “star.”

PAPILLAE … Tiny projections surrounding the NECTARIES in certain lilies, giving a “whiskered” look. (Examp. L. speciosum and L. henryi) Glossary

Variety for Pollinators

Growing a wide variety of flowers helps to feed important populations of the pollinators, and it is our tendency toward “monoculturegrowing one sort of plant” that has created many of our disturbances in the environment. Bees are struggling, and a reason given is that they are starving for more plants with pollen and nectar in the long expanses of flowerless lawns.

Some bird populations have less of the foods and habitats they thrive within, and certain insects have a heyday due to large territories of the same plant they love to attack.

Flowers have many forms, some of which are highly selective to specific pollinators.

Flower Forms:

Regular or Actinomorphic

– Floral parts, especially the corolla, are symmetrical with all sections equal in four quarters. Illustration of Floral Parts.

Inflorescence Types:

Raceme | Spike | Corymb | Umbel | Spadix| Cyme | Cincinnus | Bostryx | Rhipidium | Drepanium | Dichasium| Umbelliform Ccyme | Botryoid | Panicle | Thyrsoid | Calathid

Illustrations of the inflorescence forms Corolla types.

Irregular or Zygomorphic

– Floral parts are not symmetrical, halves, upper and lower, are unequal and dissimilar. Three types of these: 1. Papilionaceous (pea-type) -five petals of keel,banner, and wing type 2. Labiate (mints) -tube split into two parts; upper with two petals, and lower of of three petals. 3. Orchidaceous (Orchids)-three sepals and three petals with one petal creating a “lip”.


Flower Form

Flower forms

Flower forms

See larger picture.