rangeland exam 1

Auricle

Appendages on edges of the collar opposite of the lead blade on some grasses (not all have them)

Blade

The distal expanded part of a grass leaf

Collar

A thin band at the junction of the leaf blade and sheath

Crown

The base and primary ‘core’ of the plant; comprised of meristematic tissue which produce above ground shoots and below ground roots. In perennial herbs this is the constant “living” portion of the plant

Culm

The stem

Internode

the part of the culm that is between two nodes

Leaf

contains chloroplasts

Ligule

membraneous outgrowth at the inner side of the leaf sheath at its junction with the blade at the collar

Node

swollen region on the culm that produces the lead sheath

Phytomer

The basic repeating unit of a grass tiller; consists of a node, internode, leaf sheath, and blade

Sheath

lower part of the leaf that enclosed the internode 

Tiller

Entire culm and associated structures of a grass plant

Inflorescence types

Spike, Raceme, Panicle

Spike

all spikelets directly connected to the rachis

Raceme

spikelets connected one branch off the rachis

Panicle

Some spikelets connected two or more branches off of the rachis

Awn

Fibrous bristle extending from the florets (why foxtails suck)

Glumes

Pair grown from the base of a grass spikelet

Floret

The individual unit of a spikelet

Pedicel 

A short stem segment directly supporting a flower 

Peduncle

Upper most culm segment which supports the whole inflorescence/seed head

Rachis

An extension of the peduncle where the spikelets or supporting branches containing spikelets are attached

Spikelet

The basic unit of a grass inflorescence, usually composed of two glumes and one or more florets

Rhizome

underground stem/roots

Stolon

above ground stem/roots

Annual growth

entire plant germinates, grows, makes seed, and dies in a single growing season

Perennial growth

Plant can survive 3+ years; some parts grow only for 1 season then die and are replaced in next season

monocot

single leaf at germination, parallel leaf veins, fibrous roots

Dicot

Two leaves at germination, netted leaf veins, taproots

Apical

stem cells at the tips

Intercalary/basal

stem cells in the middle

Axillary/lateral

stem cells at the sides

Bracts

modified or specialized leaves, often associated with reproductive structures like flowers, inflorescence axes or cone scales

Lemma

single bract covering the top of each individual floret

Palea

single bract covering the underside of each individual floret