Grass and Legume Morphology

Question 1

What is plant morphology?

Answer 1

The study of plant form and structure
* Arrangement of plant structure
* Provides a foundation for discussing physiology (growth,
function, response)

Question 2

Grass plants are made up of a series of parts or units called “_” ?

Answer 2

Tillers

Question 3

What do tillers grow?

Answer 3

Tillers grow their own:
* Stems (culms)
* Leaves
* Roots

Question 4

What are the types of grass tillers?

Answer 4

Vegatative tiller
* Grows leavs and roots

Reproductive tillers
* Grow leaves, culm (stem), and roots

Vegatative tillers are more nutrient dense and palatable
Reproduvtive tillers are good for hay (selling hay by tons) –> produces more dry matter

Question 5

Main parts of a Grass Plant

What is the leaf blade?

Answer 5

Part of leaf above the sheath, also known as the lamina.

Question 6

Main parts of a Grass Plant

What is the leaf sheath?

Answer 6

Lower section of leaf that attaches to node and wraps around culm.

Question 7

Main parts of a Grass Plant

What is the leaf?

Answer 7

The leaf is comprised of both the leaf blade and the leaf sheath

Question 8

Main parts of a Grass Plant

What is the collar?

Answer 8

Thin band of meristematic tissue at the junction of the leaf blade and sheath

Meristematic: Actively dividing cells

Where the leaf blade and sheath come together

Question 9

Main parts of a Grass Plant

What is the stem (culm)?

Answer 9

Central axis of mature grass tiller, comprised of nodes and internodes.

Question 10

Main parts of a Grass Plant

What is the node?

Answer 10

Solid (slightly swollen) region of the culm which gives rise to a leaf sheath. On some grasses, lower culm nodes may bear buds capable of producing new tillers. Most buds are non-functional.

Question 11

Main parts of a Grass Plant

What is the internode?

Answer 11

Part of the culm between two successive nodes: expansion accounts for growth

This is where the weight of the plant comes from (dry matter)

Question 12

Collar region of a Grass Plant

What is the ligule?

Answer 12

Outgrowth at the inner junction of the leaf sheath and blade, often membranous, sometimes a ring of hairs.

Question 13

Collar region of a Grass Plant

What is the auricle?

Answer 13

Claw-like appendages at the base of the blade of some grasses

Common in wheat grasses

Question 14

Why is the collar region of grass plants important?

Answer 14

Important for grass identification

Question 15

Inflorescence (seed-head)

Answer 15

Collection of flowers arranged on a common axis

Fairly mature tillers have these

Question 16

What are spikelets?

Answer 16

The flowering unit of a grass plant composed of one or more florets enclosed by 2 glumes

Question 17

What are the major inflorescence types of grasses

Answer 17

• Spike: Spikelets are attached directly to the stem in an alternating fashion
• Raceme: Spikelets are attached to pedicels on the stem
• Panicle: “Open, flowey grass” Spikelets on “branched” stalks

Question 18

What are roots?

Answer 18

Generally more fibrous and diffuse compared to legumes - allows exploration of a greater volume of soil for water and nutrients.

Question 19

What is the function of the crown?

Answer 19

• Storage of carbohydrates and proteins
• Numerous buds: can lead to the production of new tillers, rhizomes, and stolons

Question 20

Specialized Stems

What two parts define a stem?

Answer 20

Nodes and internodes

Question 21

What is the difference between stolons and rhizomes

Answer 21

Stolons: Aboveground stems
Rhizomes: Belowground stems

Question 22

What are bunchgrasses?

Answer 22

Highly compacted collection of tillers

Question 23

What classifies tiller arrangement?

Answer 23

• Depends on presence of rhizomes or stolons
• Rhizomatous and stoloniferous also called sod-forming grasses

Question 24

What does a shoot consist of?

How is it different from a tiller?

Answer 24

• Leaves
• Stems

Does not have roots

Question 25

What are the main parts of a legume plant?

Answer 25

• Leaf: Comprised of multiple leaf blades (or leaflets) attached to a petiole
• Leaflet: Individual unit of a legume leaf that, unlike grasses has net-like veination
• Petiole: Stem-like structure that attaches leaves to stems
• Stem: Central axis of legume shoot, comprised of nodes and internodes
• Node: Solid (slightly swollen) region of the stem that gives rise to leaves. Source of axillary buds from which new leaves, stems, and flowers can initiate. Leaves and stems (shoots) that arise from axillary buds contribute to plant branching. Highly branched plants are good for grazing, provide resistance to alfalfa weevil, etc
• Internode: Part of the stem between two successive nodes - expansion accounts for growth.
• Axil: Angle created where a leaf meets a stem. Axillary buds arise from nodes at this point of attachment.
• Stipules: Pairs of often leaf-like appendages (can be quite large) found at the base of leaf petioles on some legumes that enclose and protect axillary buds.