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- Brassicaceae
- Arabis
- Arabis pycnocarpa
Arabis pycnocarpa — hairy eared-rockcress
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Facts
Hairy eared-rockcress is native to North America as well as China, Japan, and eastern Russia. In New England it is found on ledges, outcrops, and calcareous rocky woodlands.
Habitat
Cliffs, balds, or ledges, ridges or ledges, talus and rocky slopes, woodlands
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Flower petal color
-
- blue to purple
- pink to red
- white
- Leaf type
- the leaves are simple (lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade edges
-
- the edge of the leaf blade has teeth
- 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 four petals, sepals, or tepals in the flower
- Fusion of sepals and petals
- both the petals and sepals are separate and not fused
- Stamen number
- 6
- Stem nodes swollen
- the stem is not swollen at the nodes
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit length
- 30–50 mm
-
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 attachment
- the anther is attached by its base to the filament
- Anther color
- the anthers show no hint of a pink, reddish or purplish tint
- Anther length
- 0.7–1 mm
- 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
- Anther tube length
- 0 mm
- Calyx growth after flowering
- the calyx does not grow to cover or partially cover the fruit
- Calyx symmetry
- there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
- Carpel hairs
- the carpels have no hairs
- Carpels fused
- the carpels are fused to one another
- Cilia on petals
- the petal margins do not have cilia
- 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 length
- 2.5–4 mm
- Filament surface
- the filament is smooth, with no hairs or scales
- Flower appearance
- the flowers appear after the leaves have appeared
- Flower description
- the flower has a superior ovary, and lacks a hypanthium
- Flower orientation
- the flower points upwards or is angled outwards
- Flower petal color
-
- blue to purple
- pink to red
- 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 style is knob-like at the tip, and unbranched
- Fringed petal edges
- the petals are not fringed
- 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
- Hairs on inflorescence
- the axis of the inflorescence has hairs entirely without glands
- 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
- 2–12 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 carpels
- 2
- Number of pistils
- 1
- Number of sepals, petals or tepals
- there are four petals, sepals, or tepals in the flower
- Number of styles
- 1
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Perianth shape
- the perianth is rotate (platter-shaped, the corolla flattened, circular, with nearly horizontally spreading lobes)
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal and sepal colors
-
- blue to purple
- pink to red
- white
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal base
- the petal narrows abruptly at the base
- Petal folds or pleats
- the petals of the flower do not have folds or plaits
- Petal glandular dots or scales
- no
- Petal hairs (Viola)
- NA
- Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
- Petal length
- 3–5 mm
- Petal length relative to sepals
- the petals are longer than the sepals
- Petal nectaries
- the petals do not have nectaries
- Petal number
- 4
- Petal shape
-
- the petal outline is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
- the petal outline is oblong (rectangular, but with rounded ends)
- the petal outline is obovate (roughly egg-shaped, but with the widest point above the middle of the leaf blade)
- the petal outline is spatulate (spoon-shaped; narrow near the base, then suddenly widening to a rounded tip)
- Petal tip shape
- the petal tip is obtuse (bluntly pointed)
- Petal tips (Cuscuta)
- NA
- Petal width
- 1–2.5 mm
- 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 auricles
- the sepals have no auricles
- Sepal cilia
- the sepals do not have cilia
- Sepal color
- green to brown
- Sepal features
- the sepals do not have any of the mentioned special features
- Sepal length
- 2.5–4 mm
- Sepal number
- 4
- Sepal orientation
-
- the sepals are pressed against the corolla, or jutting stiffly upward
- the sepals are slightly curved outwards from the corolla
- Sepal relative length
- NA
- Sepal shape
- the sepal outline is oblong (rectangular, but with rounded ends)
- Sepal texture
- the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture
- Sepal tip shape
-
- the sepal tip is acute (is sharply pointed)
- the sepal tip is obtuse (is bluntly pointed)
- Sepal uniformity
- all the sepals are about the same size
- Sepals fused only to sepals
- the sepals are separate from one another
- Spur length
- 0 mm
- Spur number
- NA
- Stamen appendages
- stamen appendages are absent
- Stamen attachment
- the stamens are not attached to the petals or tepals
- Stamen length
- 3.2–5 mm
- Stamen lengths differ
- the stamens are tetradynamous (four long stamens and two short ones)
- Stamen morphology
- the stamens within a cycle differ in length or width
- Stamen number
- 6
- Stamen position relative to petals
- NA
- Stamen relative length
- anything
- Stamens fused
- the stamens are not attached to one another
- Staminodes
- there are no staminodes on the flower
- Stigma position
- the stigmas are positioned at the tip of the style
- Style length
- 0.2–1.3 mm
- Style petal-like
- the styles are not petal-like
- Style relative length
- NA
- 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
- NA
- Capsule splitting
-
- NA
- the capsule splits by two main valves, teeth or pores
- Carpel beak length
- 0 mm
- Fruit (pyxis) dehiscence
- NA
- Fruit beak length
- 0 mm
- Fruit cross-section
-
- the fruit is at least somewhat flattened
- the fruit is round in cross-section
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 30–50 mm
- Fruit length relative to sepals
- NA
- Fruit length to width ratio
- 37.5–38.5
- Fruit locules
- two
- Fruit shape
-
- the fruit is flat or strongly compressed
- the fruit is roughly cylindrical (with parallel sides that do not taper, and flat across the top and bottom)
- 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 silique (greater than three times as long as wide, and dehisces by two valves, leaving the persistent replum to which the seeds are attached, found only in the Brassicaceae)
- Fruit width
- 0.8–1.3 mm
- Hair type on fruit
- NA
- Hairs on fruit
- the fruits are not hairy
- 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
- Placenta arrangement
- the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary
- Relative fruit length
- 0
- Rows of seeds in fruit (Brassicaceae)
- there is one row of seeds in each locule of the fruit
- Schizocarpic fruit compression
- NA
- Schizocarpic fruit segments
- 0
- Seed length
- 0.8–1.7 mm
- Seed relative length
-
- the seed is about as long as it is wide
- the seed is longer than it is wide
- Seed surface
-
- the seed is covered with reticulate markings (a netlike pattern due to splitting and rejoining of lines or ridges)
- the seed is hairless
- the seed is smooth or without clear markings
- Seeds comose
- no hairs
- Septum in fruit (Brassicaceae)
- The fruit is either not compressed or is compressed parallel to the septum; therefore, the fruit and its septum are about the same width
- 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)
- Horizontal rooting stem
- the plant does not have stolons
- Lifespan
-
- the plant lives for two years
- 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
-
- the plant has a caudex (the root mass is firm and hardened at the top)
- there is a thickened taproot 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
- NA
- Floral bracts
- the flower does not have bracts
- Flower bract length
- 0 mm
- Hairs on leaf stalk
-
- the petiole has hairs on it
- the petiole has no hairs on it
- Hairs on underside of leaf
- the underside of the leaf is fuzzy or hairy
- Hairs on upper side of leaf
-
- the upper side of the leaf is fuzzy or hairy
- 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
- alternate: there is one leaf per node along the stem
- Leaf blade base
-
- the leaf has a distinct leaf stalk (petiole)
- the leaf has no stalk
- the leaf has no stalk and at the base it clasps the stem
- Leaf blade base shape
-
- the base of the leaf blade is cordate (heart-shaped, has rounded lobes at the base)
- the base of the leaf blade is sagittate (arrow-shaped, with pointed lobes directed backwards)
- Leaf blade base symmetry
- the leaf blade base is symmetrical
- Leaf blade bloom
- the underside of the leaf has no noticeable bloom
- Leaf blade edges
-
- the edge of the leaf blade has teeth
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- the leaf blade has branched hairs
- Leaf blade length
- 10–80 mm
- Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
- Leaf blade shape
-
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is linear (very narrow with more or less parallel sides)
- the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
- the leaf blade is oblong (rectangular but with rounded ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- the leaf blade is spatulate (spoon-shaped; narrow near the base, then suddenly widening to a rounded tip)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade texture
- the leaf blade is herbaceous (has a leafy texture)
- Leaf blade vein pattern
- the major veins of the leaf blade branch, but do not rejoin
- 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 blade width
- 1–25 mm
- Leaf duration
-
- the leaves drop off in winter (or they whither but persist on the plant)
- the leaves remain green all winter
- Leaf form
- the leaves are green, with an expanded blade and a leaf-like texture
- Leaf hair orientation
- the hairs are standing up straight or curved in different directions
- Leaf sheath length
- 0 mm
- Leaf shiny
- the upper side of the leaf is dull or slightly shiny
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
-
- the leaves have leaf stalks
- the leaves have no leaf stalks, but attach directly to the stem
- Leaf stalk attachment to leaf
-
- NA
- the petiole attaches at the basal margin of the leaf blade
- Leaf stalk base
-
- NA
- the petiole base clasps the stem or sheathes the stem
- Leaf stalk length
- 5–20 mm
- Leaf teeth and lobes
-
- the edge of the leaf blade is entire (has no teeth or lobes)
- the leaf blade margin has outward-pointing teeth
- the leaf blade margin is wavy, but does not have teeth
- Leaf tip
-
- the tip of the leaf blade is acute (sharply pointed)
- the tip of the leaf blade is obtuse (bluntly pointed)
- 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 leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- 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 is one leaf 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
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- cliffs, balds, or ledges
- ridges or ledges
- talus or rocky slopes
- woodlands
-
Scent
- Plant odor
- the plant does not have much of a smell
-
Stem, shoot, branch
- Branched tendrils
- NA
- Direction of stem hairs
- the hairs point mostly upwards to outwards
- 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
- Hairs between stem nodes
- at least some of the hairs on the stem are branched
- 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
- 20–80 cm
- Stem bloom
- there is no powdery or waxy film on the stem
- Stem hair distribution
- the hairs on the stem are distributed more of less uniformly
- Stem nodes swollen
- the stem is not swollen at the nodes
- Stem orientation
- the stems are upright or angled outwards
- Stem roughness between nodes
- the stem does not feel rough
- Stem spacing
- the plant is solitary, or a few plants are growing together
- 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
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- absent
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
Subspecies and varieties
Our variety is Arabis pycnocarpa M. Hopkins var. pycnocarpa.
From Flora Novae Angliae dichotomous key
2. Arabis pycnocarpa M. Hopkins var. pycnocarpa N
hairy eared-rockcress. Arabis hirsuta (L.) Scop. ssp. pycnocarpa (M. Hopkins) Hultén; A. hirsuta (L.) Scop. var. pycnocarpa (M. Hopkins) Rollins; Turritis oblongata Raf. • CT, MA, ME, NH, VT. Ledges, rock outcrops, rocky woodlands, in regions of high-pH bedrock. Arabais pycnocarpa, which is native to North America, is frequently treated as an infraspecific form of the European Arabis hirsuta. However, the two taxa differ in geographic range, ploidy level, fruit length and venation, style morphology, and seed number (i.e., ample justification exists for recognition of two species).
Native to North America?
Yes
Sometimes confused with
- Boechera stricta:
- petals 7-10 mm long, white to pink or rose-purple, basal portion of stem without hairs or these sparse, and fruits 1.5-3.5 mm wide (vs. A. pycnocarpa, with petals mostly 3.5-5 mm long, white, basal portion of stem moderately to densely pubescent, and fruits mostly 0.8-1 mm wide). Turritis glabra: petals yellow, fruits circular in cross-section, and stem without hairs (vs. petals white, fruits compressed, and stems hairy at least near the base).
Synonyms
- Arabis hirsuta ssp. pycnocarpa (M. Hopkins) Hultén
- Arabis hirsuta var. pycnocarpa (M. Hopkins) Rollins
- Turritis oblongata Raf.