2 | Chapter 6: Poaceae

Question 1

How to Identify grasses:

____ more than any other chracter, really define the grass species

This is because grass structures are unqiue, and very small

Answer 1

Flowers

Question 2

Three characteristics of grass:

1. The flowers lack ____ and are borne between ____ in a _____
2. The leaves are flat, long and slender, and form a _____ around the stem
3. The stems are round, generally ___, and somewhat swollen at the ____.

Answer 2

1. The flowers LACK PETALS and are borne between BRACTS in a LEAFLESS INFLORESCENCE
2. The leaves are flat, long and slender, and form a SHEATH around the stem
3. The stems are round, generally HOLLOW, and somewhat swollen at the NODES

Question 3

Vegetative structures:

All grasses are _____, which means they only have one ____ which is the first “seed’ leaf that emerges from a seed

Answer 3

Monocotyledonous
Cotyledon

Question 4

Vegetative structures:

The first structure that emerges from a grass seed is a cylindrical, tube-like structure called a ____ which is rigid which is where the cotyledon leaves out of

The “tube” or “sleeve” part of the leaf is termed the ____. The degree to which it is open and the absence or presence of hairs is important.

The entire leaf then extends upwards from a ____ up the ___ and outward to the tip of the ____

Answer 4

coleoptile

Sheath

node
sheath
blade

Question 5

Vegetative structures:

The characteristics of the ____ are commonly used for grass identification

• Blade width
• Whether blade is rolled or flat
• Whether midrib is visible on surface
• Presence or absence of hairs
• If newly emerging blades are rolled or folded

The three types are (3)

Answer 5

blades

Types:
open
closed
Split with overlapping margins

Question 6

Vegetative structures:

The structures at the junction of the blade and sheathcalled the ____ is also an important characteristic

The two types of structures include:

____ finger-like projections that appear to wrap around the stem.
They can be (3)

____ small projections located between the blade and the stem
They can be (3)

Answer 6

Collar

Auricles:
Short, long, absent

Ligules:
Membranous, Hairy, Absent

Question 7

Reproductive structures:

Individual flowers of grass plants are called ____

Parts and amount (3)

Answer 7

florets

three stamens
single ovary
two stigma

Question 8

Reproductive structures:

The ovary is borne between two tiny leaf-like ____

The outer one is called the ___, the smaller inner one is the ____

It starts usually green but becomes leathery as the seed ripens

Answer 8

Bracts

Lemma

Palea

Question 9

Reproductive structures:

Lemmas are frequently ____

Florets may be borne singly or in clusters of up to ___ or more. If they are in clusters, they are called ___, each with two additional bracts called the ___ at the base

Answer 9

awned

14
spikelets
glumes

Question 10

Reproductive structures:

When the spikelets separate called ____, they either release above the glumes leaving the glumes on the plant

or below the glumes, keeping the glumes attached and separated from the plant

Answer 10

disarticulate

Question 11

A _____ inflorescence is anywhere the spikelets are not sessile or individually pediceled on the main axis

A ____ inflorescence are those in which the spikelets are sessline on the central axis or rachis

A _____ inflorescence has pedicels supporting single spikelets, where the pedicle is attached to the central axis

Answer 11

Panicle inflorescence

Spike inflorescence

Raceme inflorescence

Question 12

Scientific names:

Goose grass

Wild sugarcane

Cogon grass

Sugar cane

Carabao grass

Citronella grass

Kawayang tinik

Corn

Rice

Job’s tears

Answer 12

Eleusine indica

Saccharum spontaneum

Imperata cylindrica

Saccharum officinarum

Axonopus compressus

Cymbopogon nardus

Bambusa blumeana

Zea mays (L.)

Oryza zativa (L.)

Coix lacryma-jobi L.