Lab 5: Monocots 2 and Poales Flashcards
What are the common names for Cyperaceae, Juncaceae, and Poaceae?
Cyperaceae: sedges
Juncaceae: rushes
Poaceae: grasses
“Sedges have edges, rushes are round, grasses are hollow right down to the ground”
What are some general identification characteristics of Poaceae?
2-ranked leaves, stem round and hollow, open sheaths, ligules
What type of fruit does Poaceae produce?
Caryopsis (or grain) with the pericarp fused to the seed coat
Poaceae floral characteristics
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)
What is the basic unit of the inflorescence of a grass called?
spikelet (contains one or many florets)
What are the parts of a grass floret?
- 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)
What is a ligule?
Small appendage attached to the leaf
What is a auricle?
Small, clasping outgrowths that may or may not be present on the leaf collar
How are spikelets attached to the grass culm (a grass stem)?
Can be directly attached (sessile) or attached on short pedicels (pedicellate spikelets)
Phalaris arundinacea (Poaceae family)
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
What are some identification traits of Cyperaceae (genus Carex)?
3-ranked leaves, stems mostly triangular shaped, usually closed sheaths, unisexual flowers, spikes can be unisexual/mixed
Carex floral parts
- 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
What is the perigynium in Carex?
sac-like bract that surrounds the ovary in the female (carpellate) flowers
What type of fruit do Carex produce?
Achenes
What species of Carex did we key out in lab?
Carex lupulina
What are some identification traits of Juncaceae?
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
What type of fruit does Juncaceae produce?
Capsules with one to many seeds
What are identification traits or Typhaceae?
- All wetland plants
- Have air spaces within their leaf tissue (spongy feel)
- Long, narrow two-ranked leaves with parallel veins
What are some characteristics of Typha (genus in Typhaceae–cattail family)?
- 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
What are some characteristics of Sparganium (genus in Typhaceae–cattail family)?
- 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
