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

Sagina nodosa — knotted pearlwort

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Facts

There are two subspecies of knotted pearlwort in New England. One (Sagina nodosa ssp. nodosa) is an introduced plant that may have been introduced from ships' ballast dumps, and is currently found in Massachusetts, Maine and New Hampshire; the other (Sagina nodosa ssp. borealis) is a rare native, found in Maine and New Hampshire. Their distributions sometimes overlap.

Habitat

Cliffs, balds, or ledges, coastal beaches (sea beaches), meadows and fields, ridges or ledges

New England distribution

Adapted from BONAP data

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

North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Maine
  • Massachusetts
  • New Hampshire
Flower petal color
white
Leaf type
the leaves are simple (lobed or unlobed but not separated into leaflets)
Leaf arrangement
opposite: there are two leaves per node along the stem
Leaf blade edges
the edge of the leaf blade is entire (has no teeth or lobes)
Flower symmetry
there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
Number of sepals, petals or tepals
there are five petals, sepals, or tepals in the flower
Fusion of sepals and petals
both the petals and sepals are separate and not fused
Stamen number
  • 10
  • 8
Stem nodes swollen
the stem is swollen at the nodes
Fruit type (general)
the fruit is dry and splits open when ripe
Fruit length
3–4 mm
Show all characteristics

  • Clonal plantlets

    Bulbils
    the plant does not appear to have bulbils
    Bulblets replace flowers
    there are no bulblets where the flowers are located

  • Flowers

    Anther opening
    the anthers have narrow slits or furrows that run lengthwise along the anthers
    Anther spurs
    the anthers do not have spurs on them
    Calyx symmetry
    there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
    Carpels fused
    the carpels are fused to one another
    Cleistogamous flowers
    there are no cleistogamous flowers on the plan
    Corolla morphology
    NA
    Corolla palate
    no
    Corona lobe length
    0 mm
    Epicalyx
    the flower does not have an epicalyx
    Epicalyx number of parts
    0
    Filament surface
    the filament is smooth, with no hairs or scales
    Flower description
    the flower has a superior ovary, and lacks a hypanthium
    Flower diameter
    5–10 mm
    Flower number
    1–3
    Flower petal color
    white
    Flower reproductive parts
    the flower has both pollen- and seed-producing parts
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Flowers sunken into stem
    no
    Form of style
    the flower has two or more completely separate styles
    Fused stamen clusters
    NA
    Fusion of sepals and petals
    both the petals and sepals are separate and not fused
    Hairs on flower stalk
    • the flower stalk has hairs on it
    • the flower stalk has no hairs on it
    Horns in hoods (Asclepias)
    NA
    Hypanthium
    the flower does not have a hypanthium
    Hypanthium length
    0 mm
    Inflorescence one-sided
    the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
    Inner tepals (Rumex)
    NA
    Interior flower disk
    the flower does not have an interior disc
    Length of flower stalk
    4–12 mm
    Marks on petals
    there are no noticeable marks on the petals
    Nectar spur
    the flower has no nectar spurs
    Number of branches in umbel
    0
    Number of sepals, petals or tepals
    there are five petals, sepals, or tepals in the flower
    Number of styles
    4–5
    Ovary position
    the ovary is above the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal and sepal colors
    white
    Petal appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    Petal base
    the petal narrows gradually or does not narrow at the base
    Petal folds or pleats
    the petals of the flower do not have folds or plaits
    Petal hairs (Viola)
    NA
    Petal length
    3–4.5 mm
    Petal length relative to sepals
    the petals are longer than the sepals
    Petal number
    4–5
    Petal shape
    • the petal outline is elliptic (shaped like an ellipse; widest near the middle and tapering at both ends)
    • the petal outline is orbicular (roughly circular, as wide as long)
    Petal tips (Cuscuta)
    NA
    Raceme attachment (Veronica)
    NA
    Reproductive system
    all the flowers have both carpels and stamens (synoecious)
    Scales inside corolla
    no
    Sepal and petal color
    the sepals are different from the petals
    Sepal appearance
    the sepals are green or brown, and leaf-like in texture
    Sepal appendages
    the sepals do not have appendages on them
    Sepal appendages (Oenothera)
    NA
    Sepal color
    green to brown
    Sepal length
    2–3 mm
    Sepal number
    4–5
    Sepal orientation
    the sepals are pressed against the corolla, or jutting stiffly upward
    Sepal relative length
    NA
    Sepal shape
    • the sepal outline is oblong (rectangular, but with rounded ends)
    • the sepal outline is ovate (widest below the middle and broadly tapering at both ends)
    Sepal texture
    • the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture
    • the sepals are thin and dry, paperlike
    Sepal tip shape
    • the sepal tip is obtuse (is bluntly pointed)
    • the sepal tip is rounded
    Sepal uniformity
    all the sepals are about the same size
    Sepals fused only to sepals
    the sepals are separate from one another
    Stamen attachment
    the stamens are not attached to the petals or tepals
    Stamen number
    • 10
    • 8
    Stamen position relative to petals
    NA
    Stamens fused
    the stamens are not attached to one another
    Staminodes
    there are no staminodes on the flower
    Stigma position
    the stigmas are positioned on the inner surface of the style
    Style length
    0.5–1.5 mm
    Style petal-like
    the styles are not petal-like
    Umbel flower reproductive parts
    NA
    Upper lip of bilabiate corolla
    NA

  • Fruits or seeds

    Achene relative orientation
    NA
    Achene shape
    NA
    Achene surface (Polygonum)
    NA
    Achene type
    NA
    Berry color
    NA
    Capsule color (Viola)
    NA
    Capsule ribs
    the capsule has no prominent ribs or wings
    Capsule splitting
    the capsule splits by five main valves, teeth or pores
    Carpel beak length
    0 mm
    Fruit (pyxis) dehiscence
    NA
    Fruit features (Brassicaceae)
    NA
    Fruit length
    3–4 mm
    Fruit length relative to sepals
    the fruit is longer than its associated sepals
    Fruit locules
    one
    Fruit shape
    • the fruit is ovoid (egg-shaped)
    • the fruit is spherical
    Fruit stalk orientation
    the fruits point upward or spread or curve outward
    Fruit type (general)
    the fruit is dry and splits open when ripe
    Fruit type (specific)
    the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
    Legumes (Fabaceae)
    NA
    Mericarp length
    0 mm
    Mericarp segment shape (Desmodium)
    NA
    Other markings on berry
    NA
    Ovary stipe
    the ovary or fruit does not have a stipe
    Ovary stipe length
    0 mm
    Placenta arrangement
    the plant has free-central placentation, where the ovules develop on a central column in a compound ovary lacking septa or with septa at the base only
    Rows of seeds in fruit (Brassicaceae)
    NA
    Schizocarpic fruit compression
    NA
    Schizocarpic fruit segments
    0
    Seed length
    0.5 mm
    Seed number
    125
    Seed relative length
    the seed is longer than it is wide
    Seed surface
    • the seed has pits or depressions on it
    • the seed is smooth or without clear markings
    Septum in fruit (Brassicaceae)
    NA
    Wings on fruit
    the fruit does not have wings on it
    prickles on fruits
    the fruits do not have thorn-like defensive structures

  • Glands or sap

    Glands on leaf blade
    the leaf blades do not have glandular dots or scales
    Sap
    the sap is clear and watery
    Sap color
    the sap is clear

  • Growth form

    Growth form
    the plant is an herb (it has self-supporting stems)
    Lifespan
    the plant lives more than two years
    Parasitism
    the plant is not parasitic
    Plant color
    the leaves or young stems of the plant are green
    Plants darken when dry
    no
    Spines on plant
    the plant has no spines
    Underground organs
    there are only slender roots on the plant

  • Leaves

    Bracteole edges
    NA
    Bracteole length
    0 mm
    Bracteole number (Apiaceae)
    0
    Bracteole shape
    NA
    Bracteoles
    there are no bracteoles on the plant
    Bracts in plantain (Plantago)
    NA
    Final leaf segment length (compound lvs only)
    0 mm
    Final leaf segment length to width ratio (compound lvs only)
    0
    Final leaf segment width (compound lvs only)
    0 mm
    Floral bract texture
    the floral bracts are green, with a leaf-like texture
    Floral bracts
    the flower has one or more bracts associated with it
    Hairs on leaf stalk
    NA
    Hairs on underside of leaf
    the underside of the leaf is not hairy, or it has very few hairs
    Hairs on upper side of leaf
    the upper side of the leaf is not hairy, or it has very few hairs
    Hooked hairs on underside of leaf
    no
    Inflated hairs on leaf
    the leaf blade does not have inflated hairs on it
    Leaf arrangement
    opposite: there are two leaves per node along the stem
    Leaf blade base
    the leaf has no stalk
    Leaf blade bloom
    the underside of the leaf has no noticeable bloom
    Leaf blade edges
    the edge of the leaf blade is entire (has no teeth or lobes)
    Leaf blade hairs
    the leaf blade has hairs with glands at their tips
    Leaf blade length
    1–30 mm
    Leaf blade primary vein pattern
    the secondary veins branch off at intervals from the primary vein
    Leaf blade shape
    • the leaf blade is linear (very narrow with more or less parallel sides)
    • the leaf blade is subulate (awl-shaped; narrowly tapering from the base to the tip)
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade texture
    • the leaf blade has a fleshy or spongy texture
    • the leaf blade is scarious (thin and dry like paper) or membranaceous (thin and flexible and almost translucent like a membrane)
    Leaf blade veins
    the leaf blade has one main vein running from the base towards the tip (it may or may not have secondary veins)
    Leaf duration
    the leaves drop off in winter (or they whither but persist on the plant)
    Leaf form
    the leaves are green, with an expanded blade and a leaf-like texture
    Leaf sheath length
    0 mm
    Leaf spines
    there are no spines on the leaf edges
    Leaf stalk
    the leaves have no leaf stalks, but attach directly to the stem
    Leaf stalk attachment to leaf
    NA
    Leaf stalk base
    NA
    Leaf stalk length
    0 mm
    Leaf teeth and lobes
    the edge of the leaf blade is entire (has no teeth or lobes)
    Leaf tufts in axils
    there are no clusters of smaller leaves growing out of axils
    Leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets)
    Leaf types
    There is a gradual change in appearance of the leaves from the base (or near the base) of the plant to those from further up on the stem, with leaves progressively changing as one moves higher on the stem (often becoming shorter, or less toothed/lobed, and/or with shorter petioles).
    Leaf variation
    the lower leaves are larger, toothier, and/or on longer stalks than the upper leaves
    Leaflet number
    0
    Leaflet petiolules
    NA
    Leaves per node
    there are two leaves per node along the stem
    Pinnately compound leaf type
    NA
    Specific leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets)
    Stipels
    NA
    Stipule edges
    NA
    Stipule features
    NA
    Stipule fused to leaf stalk
    NA
    Stipule length
    0 mm
    Stipule shape
    NA
    Stipules
    there are no stipules on the plant
    Teeth per side of leaf blade
    0

  • Place

    Habitat
    terrestrial
    New England state
    • Maine
    • Massachusetts
    • New Hampshire
    Specific habitat
    • cliffs, balds, or ledges
    • meadows or fields
    • ridges or ledges
    • sea beaches

  • Scent

    Plant odor
    the plant does not have much of a smell

  • Stem, shoot, branch

    Branched tendrils
    NA
    Flowering stem cross-section
    the flowering stem is circular, or with lots of small angles so that it is roughly circular
    Hair between stem nodes
    • the stem has hairs between the nodes
    • the stem has no hairs between the nodes
    Hairs between stem nodes
    • at least some of the hairs on the stem have glands
    • the stem has no hairs between the nodes
    Hooked hairs on stem between nodes
    no
    Leaves on stem
    there is at least one full leaf above the base of the flowering stem
    Plant height
    5–35 cm
    Stem nodes swollen
    the stem is swollen at the nodes
    Stem orientation
    • the stems are upright or angled outwards
    • the stems trail at the base, but may turn upwards at the tips
    Stem roughness between nodes
    the stem does not feel rough
    Stem spacing
    the plant is growing in tufts, or compact clusters with closely spaced stems, or it is densely matted together in clumps, cushionlike
    Stem succulence
    the stems are not succulent
    Tendril origin
    NA
    Tendrils
    the plant does not have tendrils
    Wings on stem
    the stem does not have wings on it

Wetland status

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

In New England

Distribution

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

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
unranked (S-rank: SNR)

ssp. borealis

New Hampshire
historical (S-rank: SH), endangered (code: E)

ssp. nodosa

Massachusetts
unrankable (S-rank: SU), #NAME? (code: #NAME?)

Subspecies and varieties

Sagina nodosa (L.) Fenzl ssp. nodosa is non-native and known from MA, ME, NH.S. nodosa ssp. borealis Crow is native and known from ME, NH. It is of conservation concern.

From Flora Novae Angliae dichotomous key

4.  Sagina nodosa (L.) Fenzl nC

knotted pearlwort.  4a. Sagina nodosa (L.) Fenzl var. borealis (Crow) Cronq.;  4b. Sagina nodosa (L.) Fenzl var. glandulosa (Bess.) Aschers.; S. nodosa (L.) Fenzl var. pubescens (Bess.) Mert. & Koch; Spergella nodosa (L.) Reichenb.; Spergula nodosa L. • MA, ME, NH. Open, coastal fields, headlands, turfs, and upper beaches, often on thin soils over ledge, in rock crevices, 
or among stones.

1a.  Stems and leaf blades glabrous; pedicels and sepals often glabrous (sometimes stipitate-glandular) … 4a. S. nodosa ssp. borealis Crow

1b.  Stems and usually the leaf blades stipitate-glandular [Fig. 566]; pedicels and sepals stipitate-glandular [Fig. 566] … 4b. S. nodosa ssp. nodosa

Subspecies borealis is known from ME, NH. It is native and of conservation concern. 
Subspecies nodosa is known from MA, ME, NH. It is non-native. The two subspecies 
sometimes co-occur in populations (e.g., Little Moose Island, Hancock County, ME, Isles 
of Shoals, Rockingham County, NH).

Native to North America?

Yes and no (some introduced)

Sometimes confused with

Sagina procumbens:
petals usually 4 per flower, usually 0.8-1 mm long, shorter than to approximately as long as the sepals and plants completely devoid of hairs (vs. S. nodosa, with petals usually 5 per flower, 3-4.5 mm long, approximately twice as long as the sepals, and usually the upper parts of plant with minute, stipitate glands).

Synonyms

  • Sagina nodosa var. glandulosa (Bess.) Aschers.
  • Sagina nodosa var. pubescens (Bess.) Mert. & Koch
  • Spergella nodosa (L.) Reichenb.
  • Spergula nodosa L.

Family

Caryophyllaceae

Genus

Sagina