Interactive Key to the Grasses of Columbia Basin

The pollen-bearing part of the stamen, borne on a filament in grasses.

Pertaining to the apex or tip of a plant organ.

Pressed flat against or close to another organ, as flowerhead branches are pressed against the axis, or hairs against a stem or leaf.

Pertaining to the unforested zone that occurs north of the tree line.

Rising upward, as stems that curve upward from the base; or branches of a flowerhead that extend upward from the stem axis at an angle of about 40º-70º.

Projecting lobes or appendages of leaf tissue, usually paired, and arising from the junction of the leaf sheath and the blade. Projecting on either side of the collar.

A slender bristle-like projection from the back or tip of the lemma or glume of some grasses. May be straight or bent.

General term for a central, supporting grass organ e.g. a rachilla or in particular, the main or central stem of a compound flowerhead.

That part near to, or forming part of, the base. In grasses, leaves can grow from the base or along the stem.

Long, often stiff, hairs at the base of the lemma. In some genera their presence is a key feature to identification.

Biogeoclimatic Zone. Ecosystem classification system used in British Columbia, with 14 broad climatically distinct areas which are further differentiated by distinct patterns of vegetation and soil.

Growing for two years -- usually producing flowers and fruit in the second year.

Broad upper part of the leaf that attaches to the sheath (the lower part of the leaf), and extends away from the stem.

Vulnerable or rare species or subspecies (taxon) that is of special concern because of characteristics that make it particularly sensitive to human activities or natural events. Taxa are listed by the British Columbia Conservation Data Centre. A Blue-listed taxon could become Red-listed in the forseeable future.

Bluish green colour of the leaves, stem or spikelets characteristic of some grasses, sometimes due to a waxy or dusty covering. Also called glaucous.

Any of the reduced or modified leaves of the flowerhead and upper part of a shoot; in grasses, the glumes and lemmas are bracts.

In this treatment, refers to a flowerhead with a main axis and small side branches. Ranges from very and spikelike to diffuse and open. Check carefully for branches if your flowerhead looks like a spike.

A grass growth form that produces numerous closely spaced shoots from the crown. The current year's leaf growth usually arises at the base, and the previous year's sheaths can persist.

Growing in tufts i.e. with several or many stems growing closely together. Referred to as tufted in this treatment.

A hard projection at the base of the floret or spikelet that appears to be an extension of the lemma.

Scar left on the thickened base of the lemma.

The fruit of grasses; the grain or seed.

Having a fringe of hairs on the margin.

Surrounding or holding tightly, as a type of auricle.

Junction zone of the leaf sheath and blade, site of the ligule and auricles when present.

Unusually flattened in one plane as the spikelets of some grasses. The spikelet can be compressed across the back so that the glumes and lemma appear flattened (dorsal) or from the sides so that the spikelet or the glumes appears keeled (lateral).

Inflorescence is narrow and dense, with the spikelets closely spaced. Occurs because the branches and the internodes are short.

The above-ground stem of a grass. Referred to as the stem in this treatment.

Part of the plant that falls away at the end of its normal function. Awns are sometimes deciduous.

With a horizontal or inclined base that curves upward into an erect or ascending tip; as in some grass stems.

Small or poorly developed; the condition of impoverished or dwarfed plants that are below average size.

Bending or arching downward, especially as the tips of flowerhead branches weighted down by spikelets.

Confined to a particular, often relatively small, geographic area.

A lemma with a functional flower inside it, either male (anther) or female (ovary). If you find any parts inside the lemma at all you can consider it a fertile lemma. See also sterile lemma.

Flexed, having relatively firm bends. Usually refers to stem or branches of the flowerhead.

The basic unit of a grass spikelet, consists of one flower subtended and usually enclosed by the lemma and the palea.

Abruptly and clearly bent or twisted.

One of a pair of bracts, found at the base of and enclosing a grass spikelet.

Bearing hairs (trichomes) of any sort. In this treatment, it refers to hairs which can be seen with a field lens.

Herblike, thin in texture and green, as opposed to woody.

Thin and translucent or transparent.

Hardened; firm; retaining its shape when squeezed.

The flowering part of the grass, borne at the end of the stem. It can be a spike or branching. Also called the flowerhead.

The part of a stem (culm) between two successive nodes.

Plant origins from outside western North America. Introduction is either accidental or intentional.

Rolled inwards, as the margins of a grass leaf blade, exposing the lower surface and concealing or partially concealing the upper surface.

Having a conspicuous sharp fold or ridge along the back of a compressed sheath, blade, glume or lemma, especially in Bromus.

Lance-shaped, long and tapered to a point.

The outer, usually larger (away from the axis) bract of the pair of bracts that enclose a grass flower. The inner bract is called the palea.

Outgrowth of tissue at the inner junction of the leaf-sheath and blade, partially surrounding the stem. Usually membraneous, but can be only a fringe hairs.

The first glume (adjacent to the axis). It is usually smaller than the upper glume. In some grasses, the lower glume is reduced or absent.

Pertaining to low-elevation coastal areas in B.C.

Referring to those grasses with native and introduced populations within species in B.C.

Pertaining to mountain slopes, and often, in particular, to the mostly forested zone extending downslope from the subalpine forest zone.

The place of origin is North America. In the case of circumpolar or circumboreal species these are considered to be native in this treatment.

A longitudinal vein of a leaf, lemma or other organ, often raised above the surface.

Hanging or bent to the side, as in the tip of a grass flowerhead that is not erect.

The part of a stem to which a leaf is attached; in grasses, it is often swollen and hard. The base of the sheath attaches at a node. The measurement for sheath opening should be taken from the node to the collar.

The structure that encloses the young, undeveloped seeds.

The inner (toward the axis) of the pair of bracts that enclose a grass flower.

A compoundly branched flowerhead, as in many grasses.

The stalk of a single flower; in grasses, the stalk of a single spikelet, attaching the spikelet to the main or branch axis.

Growing for more than two growing seasons usually flowering each year.

Remaining attached to the axis after maturity.

Shaped as the forward part of a ship; said of some grass leaf blade tips that have their margins turned upward -- and sometimes inwards as well - resembling a ship's prow. See also keeled.

Having short, soft hairs; sometimes loosely used for bearing hairs (trichomes) of any sort i.e. hairy.

A flowerhead with stalked florets arranged singly along the elongated, unbranched axis.

The axis of a spikelet.

In grasses, the main or central stem of a simple (non-compound) flowerhead such as that of a spike (compare axis).

A candidate (as of 2002) for legal designation as an endangered, threatened or extirpated species. An endangered species is an indigenous species facing extinction in B.C. A threatened species is one that is likely to become extinct if limiting factors are not reversed. An extirpated species no longer exists in the wild in B.C. but does occur elsewhere.

The underground stem of a plant (a root-stem); has both roots and shoots at the nodes.

The part of a grass leaf that wraps around the stem. The leaf blade attaches to the end of the sheath at the collar. It is important to distinguish the sheath from the stem.

An unbranched flowerhead; spikelets are stalkless.

The compact unit of the flowerhead consisting of one or two glumes at the base and one to several flowers borne on the spikelet axis.

Directed outward; in grasses, often used to refer to hairs on an organ e.g. a leaf sheath, or to flowerhead branches that form an angle with the axis between that of upright and perpendicular i.e. between about 70º-90º.

A lemma with no functional flower or flower parts inside. In this treatment, sterile lemmas are not counted as florets.

Above-ground stem of a plant that produces roots and shoots at the nodes.

Pertaining to the forest zone immediately below the alpine zone.

Unforested vegetation below the lower treeline; largely confined to valley bottoms and lower slopes; includes prairie vegetation. Also called the steppe zone.

Variously the area between or the angle formed by the upper margins of the leaf sheath.

As if chopped off, having the apex or base of an organ transversely straight or nearly straight.

Growing in clumps with several stems growing closely together. See cespitose.

The second of the two glumes (towards the tip of the spikelet), often larger than the lower glume.

	GLOSSARY
	A B C D E F G H I J K L M N O P Q R S T U V W X
	Alpine:	Above the tree line in mountains, or open habitats at tree line.
	Annual:	Completing the life-cycle (seed to seed) in one growing season then dying.
	Anther:	The pollen-bearing part of the stamen, borne on a filament in grasses.
	Apical:	Pertaining to the apex or tip of a plant organ.
	Appressed:	Pressed flat against or close to another organ, as flowerhead branches are pressed against the axis, or hairs against a stem or leaf.
	Arctic:	Pertaining to the unforested zone that occurs north of the tree line.
	Ascending:	Rising upward, as stems that curve upward from the base; or branches of a flowerhead that extend upward from the stem axis at an angle of about 40º-70º.
	Auricles:	Projecting lobes or appendages of leaf tissue, usually paired, and arising from the junction of the leaf sheath and the blade. Projecting on either side of the collar.
	Awn:	A slender bristle-like projection from the back or tip of the lemma or glume of some grasses. May be straight or bent.
	Axis:	General term for a central, supporting grass organ e.g. a rachilla or in particular, the main or central stem of a compound flowerhead.
	Basal:	That part near to, or forming part of, the base. In grasses, leaves can grow from the base or along the stem.
	Bearded:	Long, often stiff, hairs at the base of the lemma. In some genera their presence is a key feature to identification.
	BEC :	Biogeoclimatic Zone. Ecosystem classification system used in British Columbia, with 14 broad climatically distinct areas which are further differentiated by distinct patterns of vegetation and soil.
	Biennial:	Growing for two years -- usually producing flowers and fruit in the second year.
	Blade:	Broad upper part of the leaf that attaches to the sheath (the lower part of the leaf), and extends away from the stem.
	Blue-Listed:	Vulnerable or rare species or subspecies (taxon) that is of special concern because of characteristics that make it particularly sensitive to human activities or natural events. Taxa are listed by the British Columbia Conservation Data Centre. A Blue-listed taxon could become Red-listed in the forseeable future.
	Bluish	Bluish green colour of the leaves, stem or spikelets characteristic of some grasses, sometimes due to a waxy or dusty covering. Also called glaucous.
	Bract:	Any of the reduced or modified leaves of the flowerhead and upper part of a shoot; in grasses, the glumes and lemmas are bracts.
	Branched:	In this treatment, refers to a flowerhead with a main axis and small side branches. Ranges from very and spikelike to diffuse and open. Check carefully for branches if your flowerhead looks like a spike.
	Bunchgrass:	A grass growth form that produces numerous closely spaced shoots from the crown. The current year's leaf growth usually arises at the base, and the previous year's sheaths can persist.
	Caespitose:	Growing in tufts i.e. with several or many stems growing closely together. Referred to as tufted in this treatment.
	Callus:	A hard projection at the base of the floret or spikelet that appears to be an extension of the lemma.
	Callus-scar:	Scar left on the thickened base of the lemma.
	Caryopsis:	The fruit of grasses; the grain or seed.
	Ciliate:	Having a fringe of hairs on the margin.
	Clasping:	Surrounding or holding tightly, as a type of auricle.
	Collar:	Junction zone of the leaf sheath and blade, site of the ligule and auricles when present.
	Compressed:	Unusually flattened in one plane as the spikelets of some grasses. The spikelet can be compressed across the back so that the glumes and lemma appear flattened (dorsal) or from the sides so that the spikelet or the glumes appears keeled (lateral).
	Contracted:	Inflorescence is narrow and dense, with the spikelets closely spaced. Occurs because the branches and the internodes are short.
	Culm:	The above-ground stem of a grass. Referred to as the stem in this treatment.
	Deciduous:	Part of the plant that falls away at the end of its normal function. Awns are sometimes deciduous.
	Decumbent:	With a horizontal or inclined base that curves upward into an erect or ascending tip; as in some grass stems.
	Depauperate:	Small or poorly developed; the condition of impoverished or dwarfed plants that are below average size.
	Drooping:	Bending or arching downward, especially as the tips of flowerhead branches weighted down by spikelets.
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	Endemic:	Confined to a particular, often relatively small, geographic area.
	Erect:	Standing upright.
	Fertile lemma:	A lemma with a functional flower inside it, either male (anther) or female (ovary). If you find any parts inside the lemma at all you can consider it a fertile lemma. See also sterile lemma.
	Flexuous:	Flexed, having relatively firm bends. Usually refers to stem or branches of the flowerhead.
	Flower or Floret:	The basic unit of a grass spikelet, consists of one flower subtended and usually enclosed by the lemma and the palea.
	Geniculate:	Abruptly and clearly bent or twisted.
	Glume:	One of a pair of bracts, found at the base of and enclosing a grass spikelet.
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	Hairy:	Bearing hairs (trichomes) of any sort. In this treatment, it refers to hairs which can be seen with a field lens.
	Herbaceous:	Herblike, thin in texture and green, as opposed to woody.
	Hyaline:	Thin and translucent or transparent.
	Indurate:	Hardened; firm; retaining its shape when squeezed.
	Inflorescence:	The flowering part of the grass, borne at the end of the stem. It can be a spike or branching. Also called the flowerhead.
	Internode:	The part of a stem (culm) between two successive nodes.
	Introduced:	Plant origins from outside western North America. Introduction is either accidental or intentional.
	Inrolled/ Involute	Rolled inwards, as the margins of a grass leaf blade, exposing the lower surface and concealing or partially concealing the upper surface.
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	Keeled:	Having a conspicuous sharp fold or ridge along the back of a compressed sheath, blade, glume or lemma, especially in Bromus.
	Lanceolate:	Lance-shaped, long and tapered to a point.
	Lemma:	The outer, usually larger (away from the axis) bract of the pair of bracts that enclose a grass flower. The inner bract is called the palea.
	Ligule:	Outgrowth of tissue at the inner junction of the leaf-sheath and blade, partially surrounding the stem. Usually membraneous, but can be only a fringe hairs.
	Lower glume:	The first glume (adjacent to the axis). It is usually smaller than the upper glume. In some grasses, the lower glume is reduced or absent.
	Lowland:	Pertaining to low-elevation coastal areas in B.C.
	Mixed:	Referring to those grasses with native and introduced populations within species in B.C.
	Montane:	Pertaining to mountain slopes, and often, in particular, to the mostly forested zone extending downslope from the subalpine forest zone.
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	Native:	The place of origin is North America. In the case of circumpolar or circumboreal species these are considered to be native in this treatment.
Nerve:	A longitudinal vein of a leaf, lemma or other organ, often raised above the surface.
Nodding:	Hanging or bent to the side, as in the tip of a grass flowerhead that is not erect.
Node:	The part of a stem to which a leaf is attached; in grasses, it is often swollen and hard. The base of the sheath attaches at a node. The measurement for sheath opening should be taken from the node to the collar.
Ovary:	The structure that encloses the young, undeveloped seeds.
Palea:	The inner (toward the axis) of the pair of bracts that enclose a grass flower.
Panicle:	A compoundly branched flowerhead, as in many grasses.
Pedicel:	The stalk of a single flower; in grasses, the stalk of a single spikelet, attaching the spikelet to the main or branch axis.
Perennial:	Growing for more than two growing seasons usually flowering each year.
Persistent:	Remaining attached to the axis after maturity.
Prowed:	Shaped as the forward part of a ship; said of some grass leaf blade tips that have their margins turned upward -- and sometimes inwards as well - resembling a ship's prow. See also keeled.
Pubescent:	Having short, soft hairs; sometimes loosely used for bearing hairs (trichomes) of any sort i.e. hairy.
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Raceme:	A flowerhead with stalked florets arranged singly along the elongated, unbranched axis.
Rachilla:	The axis of a spikelet.
Rachis:	In grasses, the main or central stem of a simple (non-compound) flowerhead such as that of a spike (compare axis).
Red-Listed:	A candidate (as of 2002) for legal designation as an endangered, threatened or extirpated species. An endangered species is an indigenous species facing extinction in B.C. A threatened species is one that is likely to become extinct if limiting factors are not reversed. An extirpated species no longer exists in the wild in B.C. but does occur elsewhere.
Reflexed:	Bent backward.
Rhizomatous:	Having rhizomes.
Rhizome:	The underground stem of a plant (a root-stem); has both roots and shoots at the nodes.
Sheath:	The part of a grass leaf that wraps around the stem. The leaf blade attaches to the end of the sheath at the collar. It is important to distinguish the sheath from the stem.
Spike:	An unbranched flowerhead; spikelets are stalkless.
Spikelet:	The compact unit of the flowerhead consisting of one or two glumes at the base and one to several flowers borne on the spikelet axis.
Spreading:	Directed outward; in grasses, often used to refer to hairs on an organ e.g. a leaf sheath, or to flowerhead branches that form an angle with the axis between that of upright and perpendicular i.e. between about 70º-90º.
Steppe:	See submontane.
Sterile lemma:	A lemma with no functional flower or flower parts inside. In this treatment, sterile lemmas are not counted as florets.
Stolon:	Above-ground stem of a plant that produces roots and shoots at the nodes.
Subalpine:	Pertaining to the forest zone immediately below the alpine zone.
Submontane:	Unforested vegetation below the lower treeline; largely confined to valley bottoms and lower slopes; includes prairie vegetation. Also called the steppe zone.
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Throat:	Variously the area between or the angle formed by the upper margins of the leaf sheath.
Truncate:	As if chopped off, having the apex or base of an organ transversely straight or nearly straight.
Tufted:	Growing in clumps with several stems growing closely together. See cespitose.
Upper glume:	The second of the two glumes (towards the tip of the spikelet), often larger than the lower glume.
Vernation:	The arrangement of the youngest leaf in the bud shoot. In grasses, the leaf can be rolled or folded in the bud shoot. This characteristic can be helpful in identifying immature grasses.
Viviparous:	Sprouting or germinating on the parent plant, usually by producing bulbils on the flowerhead of some grasses.


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