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• Poaceae
• Poaceae Group 3
• Anthoxanthum
• Anthoxanthum hirtum

Anthoxanthum hirtum — northern sweet grass

Facts

Northern sweet grass has a circumpolar distribution including parts of North America, but it is considered introduced in New England. Its stems release a vanilla-like scent on drying, and partly for this reason it has a number of traditional uses. It has been used by native Americans for ceremonial and practical purposes including as an incense, a fragrance, a fiber to weave baskets and mats, and to stuff pillows and mattresses. Infusions of northern sweetgrass were used to treat colds, coughs and fever.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields, shores of rivers or lakes

Characteristics

• Flowers

  Anther length

  1.2–2.1 mm

  Anther number

  2–3

  Awn on glume

  the glume has no awn

  Bristles below spikelets

  no

  Floret lower bract texture

  the lemma is hard and firm

  Floret types within spikelet

  all the florets within a spikelet are similar

  Glume awn length

  0 mm

  Glume keel

  the glume keels are smooth and hairless

  Glume relative length

  both glumes are as long or longer than all of the florets

  Glume shape

  the glume is V-shaped in cross-section

  Glume veins

  • 1
  • 3
  • 5

  Glumes per spikelet

  2

  Inflorescence arrangement

  the spikelets are uniform

  Inflorescence axis orientation

  • the inflorescence axis is arched or curved outward
  • the inflorescence axis is straight

  Inflorescence branches

  the flowers are attached to branches rather than to the main axis of the inflorescence

  Inflorescence crowding

  the panicle is somewhat to very spread out, with clearly-evident branches

  Inflorescence length

  50–150 mm

  Inflorescence length to width ratio

  1.5–2.5

  Inflorescence type (general)

  the spikelets are borne on stalks or on branches

  Inflorescence type (specific)

  the inflorescence is branched, and the branches do NOT both grow from the same side of the plant AND look like spikes

  Inflorescence width

  20–100 mm

  Inforescence position

  the spikelets are mainly carried at the end of the stem

  Lemma awn base

  • NA
  • the awn is attached right at the tip of the lemma

  Lemma awn coiled

  the lemma awn is straight or twisted, but not coiled one half turn

  Lemma awn length

  0.1–1 mm

  Lemma awn number

  • the lemma has no awn
  • the lemma has one awn on it

  Lemma awn orientation

  the awn of the lemma is straight

  Lemma cross-section

  the lemma is V-shaped if you cut across the midpoint

  Lemma hairs

  the lemma has fine hairs between the veins

  Lemma keel hairs

  the keel of the lemma is rough, or has fine hairs

  Lemma marginal vein hairs

  the marginal vein of the lemma has fine hairs on it

  Lemma surface

  the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)

  Lemma tip

  • the lemma tip is a simple point, with or without an awn (long narrow extension ending in a point)
  • the lemma tip is split into two or more points

  Lemma tip shape

  the lemma tip tapers to a narrow point (it may or may not also have an awn or teeth at the tip)

  Lemma vein number

  3

  Lower glume relative length

  the lower glume is nearly as long, or as long as, the upper glume

  One or more florets

  there is more than one floret per spikelet

  Palea relative length

  palea is one half to fully as long as lemma

  Spikelet axis tip

  there is no extension of the spikelet axis beyond the tip of the spikelet

  Spikelet disintegration

  the spikelet breaks off below the glumes

  Spikelet length

  4–6.3 mm

  Spikelet number per node

  0

  Spikelets spiny

  the spikelets do not appear spiny

  Tip of glume

  the tip of the glume is not divided (though it may have an awn on it)

  Upper glume relative length

  the upper glume is more than one half as long as the lowest lemma

  Upper glume shape

  the upper glume is widest at or below the middle

• Growth form

  Horizontal rooting stem

  no

  Lifespan

  the plant lives more than two years

  Rhizomes

  yes

  Roots

  the plant has rhizomes (horizontal underground stem with roots growing from it)

• Leaves

  Leaf auricles

  the leaves do not have auricles

  Leaf basal lobe hairy

  NA

  Leaf blade hairs

  • the leaf blade is hairless, but it may have tiny prickles that give it a sand-papery feel
  • the leaf blade is hairy

  Leaf blade width

  2.5–5.5 mm

  Leaf ligule length

  2.5–5.5 mm

  Leaf ligule type

  the leaf ligule is in the form of a membrane

  Leaf margin glands

  there are no glands along the edges of the leaf blade

  Leaf sheath closed around stem

  the margins of the leaf sheath are overlapping and not fused together except in the basal half (or less)

  Leaf sheath color and persistence

  • the leaf sheathes are off-white to light-brown and mostly persist in older leaves
  • the leaf sheathes are reddish-brown and disintegrate or become shredded in older leaves

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont

  Specific habitat

  • man-made or disturbed habitats
  • meadows or fields
  • shores of rivers or lakes

• Stem, shoot, branch

  Plant height

  40–110 cm

  Stem spacing

  • the stems grow close together in compact clusters or tufts
  • the stems grow singly or a few together (they may form diffuse colonies)

Wetland status

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae