HAIRY ROCKCRESS
File Size: 24 KB
 
Arabis pycnocarpa  M. Hopkins
[=Arabis hirsuta  (L. ) Scop.]
Konza Prairie, Riley County, Kansas
Biennial or perennial
Height: 4-32 inches
Family: Brassicaceae - Mustard Family
Flowering Period:   May, June, July
Stems: Erect, simple or branched above.
Leaves: Basal and cauline, alternate, simple. Basal leaves with petiole .2 to .8 inch; blade spatulate, oblanceolate, or oblong, .4 to 3.2 inches long, .4 to 1 inch wide, margins entire, wavy, or dentate, surfaces sparsely to densely pubescent with simple or branched hairs. Cauline leaves sessile; blade oblong to ovate or lanceolate, .4 to 3 inches long, .12 to 1 inch wide, base nearly cordate to auricled, margins entire to dentate, lower surfaces hirsute or becoming glabrous with age.
Inflorescences: Racemes, terminal. Fruiting pedicels erect, .08 to .5 inch.
Flowers: Sepals 4, distinct, oblong, 2.5--4 mm, glabrous; petals 4, white, distinct, .14 to .2 inch, base attenuate; stamens 6, 4 long stamens barely exserted, 2 short stamens included; sigma 1.
Fruits: Siliques, sessile, strongly ascending or appressed to rachis, linear, 1.4 to 2.6 inches long, .04 to .1 inch wide, slightly flattened; seeds brown, round to oblong, .04 to .07 inch, essentially smooth, winged, sometimes obscurely so.
Habitat: Bluffs, cliffs, ledges, open floodplains, and rocky sites in tallgrass prairies.
Distribution: Northeast quarter of Kansas and Cherokee County
Origin: Native
Comments: Arabis, Arabia, and pycnocarpa, crowded carpels.

Hairy rockcress leaves
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Konza Prairie, Riley County, Kansas
Hairy rockcress inflorescence
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Konza Prairie, Riley County, Kansas
Hairy rock cress habit
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Konza Prairie, Riley County, Kansas
Hairy rock cress flowers
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Konza Prairie, Riley County, Kansas