Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

Native Plant Trust: Go Botany Discover thousands of New England plants

Dichanthelium boscii — Bosc's rosette-panicgrass

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Bosc's rosette-panicgrass is native to southern and eastern North America, reaching the northeastern limit of its range in New England, where it is found only in Connecticut and Rhode Island. It mainly inhabits oak (Quercus) and hickory (Carya) woodlands and rocky slopes.

Habitat

Ridges or ledges, talus and rocky slopes, woodlands

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Rhode Island
Leaf blade width
15–40 mm
Inflorescence branches
the flowers are attached to branches rather than to the main axis of the inflorescence
Spikelet length
3.8–5.2 mm
Glume relative length
neither glume is quite as long as all of the florets
Awn on glume
the glume has no awn
One or more florets
  • there is more than one floret per spikelet
  • there is one floret per spikelet
Lemma awn length
0 mm
Leaf sheath hair type
there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
Leaf ligule length
0.4–0.9 mm
Show all characteristics
  • Flowers

    Anther number
    3
    Awn on glume
    the glume has no awn
    Bristles below spikelets
    no
    Floret lower bract texture
    the lemma is hard and firm
    Floret number
    1–2
    Floret types within spikelet
    • NA
    • there are at least two distinct forms of florets within one spikelet
    Glume relative length
    neither glume is quite as long as all of the florets
    Glume shape
    the glume is flat or curved in cross-section
    Glume veins
    • 3
    • 5
    • 7 or more
    Inflorescence arrangement
    the spikelets are uniform
    Inflorescence axis orientation
    the inflorescence axis is straight
    Inflorescence branches
    the flowers are attached to branches rather than to the main axis of the inflorescence
    Inflorescence length
    40–120 mm
    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
    Lemma awn base
    NA
    Lemma awn coiled
    NA
    Lemma awn length
    0 mm
    Lemma awn number
    the lemma has no awn
    Lemma awn orientation
    NA
    Lemma cross-section
    the lemma is flat or rounded if you cut across the midpoint
    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)
    Lemma vein number
    • 3
    • 5
    • 7 or more
    One or more florets
    • there is more than one floret per spikelet
    • there is 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 length
    3.8–5.2 mm
    Spikelets spiny
    the spikelets do not appear spiny
    Upper glume shape
    the upper glume is widest at or below the middle
  • Growth form

    Lifespan
    the plant lives more than two years
    Roots
    the plant has a root mass with a hardened top
  • Leaves

    Basal leaves
    the plant has large or prominent tufts of leaves at the base of the flowering stem
    Leaf auricles
    the leaves do not have auricles
    Leaf blade base
    the leaf blade cuts in abruptly to the narrower base, or has rounded lobes on either side of the base (heart-shaped)
    Leaf blade width
    15–40 mm
    Leaf ligule length
    0.4–0.9 mm
    Leaf ligule type
    the leaf ligule is in the form of a membrane with fine hairs
    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 hair type
    there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
    Leaf sheath hairs
    there are hairs on the surface of the leaf sheath
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Rhode Island
    Specific habitat
    • ridges or ledges
    • talus or rocky slopes
    • woodlands
  • Stem, shoot, branch

    Stem spacing
    the stems grow close together in compact clusters or tufts

Wetland status

Not classified

In New England

Distribution

Connecticut
present
Maine
absent
Massachusetts
absent
New Hampshire
absent
Rhode Island
present
Vermont
absent

Conservation status

None

From Flora Novae Angliae dichotomous key

3.  Dichanthelium boscii (Poir.) Gould & C.A. Clark N

Bosc’s rosette-panicgrass. Panicum boscii Poir.; P. boscii Poir. var. molle (Vasey) A.S. Hitchc. 
& Chase • CT, RI. Woodlands and semi-open rocky slopes, often associated with Quercus and/or Carya.

Native to North America?

Yes

Sometimes confused with

Dichanthelium latifolium:
spikelets 2.9-3.9 mm long and nodes glabrous or sparsely pubescent with retrorsely oriented hairs as long as 1.4 mm (vs. D. boscii, with spikelets 3.8-5.2 mm long and nodes moderately to densely pubescent with retrorsely oriented hairs 1.3-3.4 mm long).

Synonyms

  • Panicum boscii Poir.
  • Panicum boscii Poir. var. molle (Vasey) A.S. Hitchc. & Chase

Family

Poaceae