''Boechera retrofracta'' is a species of flowering plant in family
Brassicaceae. The common names include reflexed rockcress.
Description
''Boechera retrofracta'' is a biennial or short-lived perennial species. The plants typically have single stems 1.5 to 7 dm (sometimes to 10.5 dm) tall. The
basal leaves
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
are densely pubescent, oblanceolate shaped, 2 to 7 mm wide, with entire margins or shallowly
dentate. The flowers are arranged into a usually unbranched
raceme
A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the s ...
with 15 to 80 flowers but sometimes having as many as 140. The flowers are pendent and the petals are white to lavender. The fruits (
siliques) are strongly reflexed (pendulous or pendent), usually appressed to
rachis at maturity.
[ The seeds have narrowly winged margins.]
Habitat
''Boechera retrofracta'' was listed as a threatened species in Minnesota in 1984 because of its rarity and the small size of its populations. In Minnesota populations are found in the Boundary Water Canoe Area in crevices on dry, north-and east-facing diabase
Diabase (), also called dolerite () or microgabbro,
is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-graine ...
cliffs, in association with other rare plants like: ''Physematium scopulinum
''Physematium scopulinum'', also called ''Woodsia scopulina'', is a deciduous perennial fern in the family Woodsiaceae, with the common name Rocky Mountain Woodsia,.
This plant is native to the western and northern United States and Canada. ...
'' (Rocky Mountain woodsia) and ''Asplenium trichomanes
''Asplenium trichomanes'', the maidenhair spleenwort, is a small fern in the spleenwort genus ''Asplenium''. It is a widespread and common species, occurring almost worldwide in a variety of rocky habitats. It is a variable fern with several subs ...
'' ssp. ''trichomanes'' (maidenhair spleenwort). There are also populations is Kittson county in dry prairie and sand dune habitat in association with xerophytes such as ''Juniperus horizontalis
''Juniperus horizontalis'', the creeping juniper or creeping cedar,Bailey, L.H.; Bailey, E.Z.; the staff of the Liberty Hyde Bailey Hortorium. 1976. ''Hortus third: A concise dictionary of plants cultivated in the United States and Canada''. Macm ...
'' (creeping juniper), '' Orthocarpus luteus'' (owl clover), and ''Houstonia longifolia
''Houstonia longifolia'', commonly known as long-leaved bluet or longleaf summer bluet, is a perennial plant in the family Rubiaceae. It can be found throughout most of the Eastern United States and Canada. It has been reported from every state e ...
'' (bluets). It has also been found in bur oak savanna. In California it is found growing on rock outcrops, in sandy soil, in grasslands and sagebrush steppes, and in open conifer forests.
Distribution
''Boechera retrofracta'' occurs in California, Alaska, western Canada, Colorado, Minnesota.
References
{{Taxonbar, from=Q15536453
retrofracta