Lab 5: Monocots 2 and Poales

Question 1

What are the common names for Cyperaceae, Juncaceae, and Poaceae?

Answer 1

Cyperaceae: sedges
Juncaceae: rushes
Poaceae: grasses

“Sedges have edges, rushes are round, grasses are hollow right down to the ground”

Question 2

What are some general identification characteristics of Poaceae?

Answer 2

2-ranked leaves, stem round and hollow, open sheaths, ligules

Question 3

What type of fruit does Poaceae produce?

Answer 3

Caryopsis (or grain) with the pericarp fused to the seed coat

Question 4

Poaceae floral characteristics

Answer 4

Most grass florets are perfect
3 stamens
Compound ovary formed from two fused carpels
Perianth is reduced to 2 tiny scales called lodicules which are at the base of each floret (almost always bisexual, but some unisexual)

Question 5

What is the basic unit of the inflorescence of a grass called?

Answer 5

spikelet (contains one or many florets)

Question 6

What are the parts of a grass floret?

Answer 6

• Upper and lower glume (bracts)
• Lemma: outer bract on the floret
• Palea: inner bract on the floret
• Awn: stiff, narrow, pointed structure that some species of grass have on either the tips or backs of one of their glumes or lemmas
• Anther
• Filament
• Stigma
• Ovary (matures into a grain/caryopsis)

Question 7

What is a ligule?

Answer 7

Small appendage attached to the leaf

Question 8

What is a auricle?

Answer 8

Small, clasping outgrowths that may or may not be present on the leaf collar

Question 9

How are spikelets attached to the grass culm (a grass stem)?

Answer 9

Can be directly attached (sessile) or attached on short pedicels (pedicellate spikelets)

Question 10

Phalaris arundinacea (Poaceae family)

Answer 10

Each floret has 1 lemma and 1 palea
Filament: stringy structure with no rigidity
3 stamens
2 stigmas = 2 carpels (bi-carpelate flower)

Spreads via seeds or pieces of stem, roots, and rhizomes

The spikelets are borne on stalks or on branches
- the spikelets are mainly carried at the end of the stem

the lemma has no awn

Question 11

What are some identification traits of Cyperaceae (genus Carex)?

Answer 11

3-ranked leaves, stems mostly triangular shaped, usually closed sheaths, unisexual flowers, spikes can be unisexual/mixed

Question 12

Carex floral parts

Answer 12

• 3 stamens
• ovary resulting from the fusion of 2-3 carpels
• Florets usually subtended by only a single bract (called a scale)
• arrangement of florets and scales can be in 2-ranks or spirally arranged
• Flowers are unisexual
  -Style protrudes from the perigynium and splits into 2 or 3 stigmas that stick out to catch pollen
• no petals/sepals

Question 13

What is the perigynium in Carex?

Answer 13

sac-like bract that surrounds the ovary in the female (carpellate) flowers

Question 14

What type of fruit do Carex produce?

Answer 14

Achenes

Question 15

What species of Carex did we key out in lab?

Answer 15

Carex lupulina

Question 16

What are some identification traits of Juncaceae?

Answer 16

3-ranked leaves, stems round, usually closed sheaths

Perianth with 6 tepals (brown and papery)

At the base of tepals are sometimes little bracts called bractioles or prophyllis

Question 17

What type of fruit does Juncaceae produce?

Answer 17

Capsules with one to many seeds

Question 18

What are identification traits or Typhaceae?

Answer 18

• All wetland plants
• Have air spaces within their leaf tissue (spongy feel)
• Long, narrow two-ranked leaves with parallel veins

Question 19

What are some characteristics of Typha (genus in Typhaceae–cattail family)?

Answer 19

• Flowers are in dense cylindrical spikes
• Male flowers at the top and female flowers below
• Fruit = achene (floats due to bristles)
• Ovary attached to a stipitate
• Male flowers = 3 stamens with bristles (not as numerous as female flowers)

Inflorescences separated into male and female sections

Question 20

What are some characteristics of Sparganium (genus in Typhaceae–cattail family)?

Answer 20

• Triangular stems
• Fruits = achenes borne in globe-shaped heads that are distinctive
• 2-ranked leaves
• Monoecious
• Perianth small scale-like tepas
• Ovaries sessile on the head
• Inflorescence globose unisexual head