Hello, my name is Steve Van Vleet.

I'm the regional extension specialist in ag

and natural resources for Washington State University.

Today, I want to talk to you about plant and weed


The first and most important part

when you're wanting to identify a weed

is to first get a picture of that weed or plant.

So you get a picture from multiple different angles

to be able to determine those characteristics of that plant.

Then after you have your photograph,

you need to record information about the characteristics.

You need to record the date, what kind of habitat

it's in, all those different characteristics

that you observe in the field.

Collect the plant

The picture's very good to have, but you

do want to collect that plant.

So you want to be able to collect the plant

and take that plant sample-- roots, stems, leaves,

seeds, all of the plant that you can--

and take that plant back to your laboratory

so that you can put it in the plant press and identify it.

Identify the plant

Before you start to identify the plant you have collected,

it's important to first narrow down

the possible plants it could be.

First, figure out what category the plant belongs to.

Is that plant a tree?

Is it a succulent herb, a shrub, a fern, a grass, a type

of broad leaf plant.

Identify the weed

And then once you have identified the plant's

category, the next step is to group

those plants that have characteristics similar

to your plant and eliminate the ones that do not.

One way to do this is the use of manual or field guide

to identify that weed or plant by its flower color.

Once you get it narrowed down to the family,

you can determine what family that weed or plant belongs to.

Dichotomous key

You might want to also try using a digital resource,

such as 1200 Weeds of the 48 States and Adjacent Canada DVD.

Another way of identifying the plants

is the use of what's called a dichotomous key.

The dichotomous key gives you choices

about the plant's characteristics

that leads to that plant's identity.

For example, a dichotomous key might


ask whether the leaves of your plant are opposite on the stem.

Depending on this answer, the key

directs you to another question about another characteristic

of the plant.

And as you follow the thread of all the characteristics,

you'll reach the plant's identification in the end.


However, the most efficient and accurate way

to identify a plant is to actually take

the sample of plant, which includes the leaves,

the stem, the roots, if possible, the seeds, also

if possible, to a trained specialist in plant


And if possible, make sure you can take the pictures along

with that and any notes that you've

taken about the characteristics of that plant

to that specialist.

When you want to identify a plant (weed), the first thing you need to do is take a picture of it. Then, collect and press the entire plant, if possible, and record information about it. Record where you collected the plant, the date you collected it, and any key characteristics you observe about the plant. The Hermiston Agricultural Research & Extension Center is located at 2121 South First Street in Hermiston, Oregon. Office hours are 8:00am - 5:00pm, Monday - Friday, closed during the lunch hour, noon - 1:00pm.

HAREC plant pathology diagnostic lab services

Catalog - EM 9122

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