[Holboell's Rockcress]- [Rockcresses: The Genus Arabis East of the Cascade Mountains of Oregon and Washington]

Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress

Boechera retrofracta

Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda

Calyx hairs of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

The photo above shows a close-up view of the flowers of Holboell's rockcress (variety retrofracta) as seen along FS Rd 4650 to the east of Table Rock in the northern Wallowa-Whitman NF.........June 26, 2008. Note the numerous starlike hairs (many held aloft by short hairs) on the calyx lobes.

Revolute leaf edges of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)The photo at right shows the leaves and stems of Holboell's rockcress (variety retrofracta) as seen along FS Rd 21 above Murderers Creek, Malheur NF........5/24/2003.

Characteristics:

Holboell's rockcress is a biennial or short-lived perennial wildflower. One to several simple (to branched above) stems arise to a height of 100 cm. The lower part of the plant is strongly haired with simple or radially branched hairs, while the herbage is smooth to uniformly hairy above. The basal leaves are typically arranged in a basal rosette of linear-oblanceolate to broad, oblanceolate-spatulate leaves which are 1-5.5 cm long and 2-7 mm wide. The blades range from entire to toothed and are typically covered with fine felt-like hairs or longer, coarse or fine hairs. The numerous stem leaves often overlap each other and are often petiolate, although the upper leaves on some varieties are clasping with heart-shaped bases. They range from lanceolate to narrowly oblanceolate in shape and 1-5 cm long and 2-7 mm wide. Their blades are typically pubescent although they may be glabrous on some varieties.

The inflorescence is a densely-flowered raceme of 20-100 white, pink or most commonly, pinkish-purple flowers. The pedicels are 5-15 mm long and either uniformly curved downwards or more commonly abruptly bent downwards at the base. The pedicels vary from glabrous to hairy. Each of the 4 sepals is glabrous to hairy and each is 2.5-5 mm long. Each of the 4 petals is 5-10 mm long. The fruits are glabrous siliques from 3-7 cm long and 1-2 mm wide.

Variety retrofracta has simple to branched stems above measuring 20-90 cm high. They have woolly-haired stems below and range from pubescent to nearly glabrous above. The basal leaves are greater than 3 mm wide with entire to toothed margins. The leaf margins of the stem leaves are noticeably rolled under. The pedicels are sharply bent downwards at their bases.


Varieties:

Variety collinsii: Stem leaves with heart-shaped bases that often clasp the stem. Petals less than 7 mm long. Pedicels bent sharply downwards at their base. The siliques are more or less straight. Found from Washington to Alberta, Wyoming and east through he Dakotas and Manitoba to Quebec.

Variety pendulocarpa: Stem leaves lack heart-shaped bases. Found from British Columbia south to California and east to Montana and Colorado.

Variety pinetorum: Stem leaves with heart-shaped bases that often clasp the stem. Basal leaves are coarsely hairy. Pedicels uniformly curved outwards and downwards, not sharply reflexed downwards at the base. The siliques are thus spreading-drooping with the tip often incurved. Found from British Columbia south to California and east to Saskatchewan and Colorado.

Variety retrofracta: Stem leaves with heart-shaped bases that often clasp the stem. Leaves with margins rolled under, the upper ones pubescent. The basal leaves are covered in short, dense, felt-like hairs. Pedicels bent sharply downwards at their base. Petals over 7 mm long. Siliques 1.5-2 mm wide and more or less straight. Found from the Yukon and British Columbia south to California and east to Alberta (and occasionally to Quebec) and Colorado.


Habitat:

Hairy rockcress is found in forests and forest openings at all elevations.


Range:

Hairy rockcress is found from the Arctic south through much of North America to California, Arizona, and New Mexico, and as far east as the mid-Atlantic states.


Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Secund rockcress observed on the hilltop above the Pine Mountain Observatory, Deschutes National Forest......May 12, 2018.

Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Stem leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Stem leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Basal leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Secund rockcress as seen along the Sprague Highway about one mile west of the junction with Miller Ranch Road, eastern Washington...........April 28, 2014.


Basal and stem leaves of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Secund rockcress blooming atop Bickleton Ridge in the Bickleton Ridge Unit of the Klickitat Wildlife Area.........May 7, 2017.

Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

What appears to be Boechera retrofracta in bloom along Forest Service Road 35 on Table Mountain, Wenatchee National Forest........June 4, 2013.

Upper stem leaves and inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Lower stem leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

The photo above shows a close-up view of the inflorescence and upper stem leaves of Holboell's rockcress (variety retrofracta) as seen along FS Rd 4650 to the east of Table Rock in the northern Wallowa-Whitman NF.......June 26, 2008.

Inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Close-ups of the inflorescence of Holboell's rock cress (var. retrofracta). Note the glabrous, spreading to reflexed pedicels and the numerous star-shaped hairs on the calyces. Photographed on Wedge Mt., Wenatchee National Forest.......June 8, 2009.

Stem leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Additional close-up views of Holboell's rockcress as seen at the Lawrence Memorial Grasslands several miles south of Shaniko, OR.........May 15, 2010.

Pendulous seed pod of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Pendulous seed pods of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Holboell's rockcress (variety retrofracta) as seen (left and center left) along FS Rd 21 above Murderers Creek, Malheur NF........5/24/2003. Note the pedicel which is curved sharply downwards. The photos at center right and right show Holboell's rockcress (var. retrofracta) as seen on a rock outcrop upstream of the group camp at Ochoco Forest Camp, Ochoco National Forest........April 30, 2016.

Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Developing fruits of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Holboell's rockcress (var. retrofracta) as seen in scablands at the northeast corner of the junction of FS Roads #42 and #3010, southeast corner of Big Summit Prairie, Ochoco National Forest..........April 29, 2016.

Stem leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Basal leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Holboell's rockcress (var. retrofracta) as seen in scablands near the junction of FS Roads #42 and #300, Ochoco National Forest and adjacent BLM lands..........April 30, 2016.

Reflexed siliques of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Basal leaves of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Reflexed rockcress as seen along the Wapaloosie Mountain Trail #15 in the Kettle Range, Colville National Forest.........June 23, 2016.

Rolled leaf margins of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda) - Inflorescence of Holboell's Rockcress, Reflexed Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

Close-up images of the rolled stem leaf margins and sharply reflexed flowers of reflexed rockcress as seen in scablands along Forest Road 30 at the east side of Big Summit Prairie, Ochoco National Forest.........May 19, 2017.

Basal leaves of Holboell's Rockcress, Second Rockcress, Secund Rockcress: Boechera retrofracta (Synonyms: Arabis holboellii, Arabis holboellii var. retrofracta, Arabis holboellii var. secunda, Arabis retrofracta, Arabis secunda, Boechera holbellii, Bochera hoboellii var. secunda)

The photo above shows the basal leaves and lower stem leaves of Holboell's rockcress (variety retrofracta) as seen along FS Rd 21 above Murderers Creek, Malheur NF........5/24/2003.

Paul Slichter