Deciphering the sexual diploid members of the Boechera suffrutescens complex (Brassicaceae, Boechereae)
Author
Morin, David P.
Biology Department, New Mexico State University, P. O. Box 30001 - MSC 3 AF, Las Cruces, New Mexico 88003, USA
david_mo@nmsu.edu
Author
Alexander, Patrick J.
Biology Department, New Mexico State University, P. O. Box 30001 - MSC 3 AF, Las Cruces, New Mexico 88003, USA
Author
Beck, James B.
Department of Biological Sciences, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, USA & Botanical Research Institute of Texas, 1700 University Drive, Fort Worth, TX 76107, USA
Author
Windham, Michael D.
Department of Biology, Duke University, 139 Biological Sciences (Box 90338), Durham, North Carolina 27708, USA
Author
Bailey, C. Donovan
Biology Department, New Mexico State University, P. O. Box 30001 - MSC 3 AF, Las Cruces, New Mexico 88003, USA
text
PhytoKeys
2018
2018-05-02
98
15
50
http://dx.doi.org/10.3897/phytokeys.98.24296
journal article
http://dx.doi.org/10.3897/phytokeys.98.24296
1314-2003-98-15
6C4AA448FFE64D0CF1552B2F8054FFD7
1244347
Boechera suffrutescens (S. Watson) Dorn, Brittonia 55: 3. 2003
Figures 3
, 9
Type
.
U.S.A.
Oregon
.
Wallowa County
/
Baker County
:
Bluffs of Snake River
and vicinity, 1881,
W.C. Cusick
919
(
holotype
: GH!; isotype: ORE)
.
GH
holotype
image - http://kiki.huh.harvard.edu/databases/specimen_search.php?mode=details&id=27057
Description.
Plants long-lived perennials, with woody caudices raised above ground level 1-5 cm, lacking crowded, persistent leaf bases; herbage without an obvious bluish cast. Fertile stems usually 1 per caudex branch, arising centrally from basal rosettes, lower parts glabrous or glabrate with 1-2(3) rayed trichomes (0.1-0.3 mm). Leaves at stem bases narrowly oblanceolate to obsubulate, 1.5-6.0 mm wide, entire, not ciliate or rarely with simple trichomes to 0.7 mm, blade surfaces usually glabrous or sparsely pubescent with 1-3(4) rayed trichomes, but occasionally plant herbage basally pubescent with short-stalked 1-4(5)-rayed trichomes (0.07-0.40 mm) if stressed or sterile; cauline leaves (4-)6-12, sometimes concealing stem proximally, the uppermost glabrous, with auricles 0.8-4.5 mm long. Inflorescences mostly unbranched, 6-12-flowered; fruiting pedicels 4-18 mm, reflexed, usually distinctly geniculate proximally but otherwise straight, glabrous. Flowers pendent at anthesis; sepals glabrous; petals purple or whitish with rose tips, 4.5-6.0 mm long
x
2.0-2.5 mm wide, glabrous; anthers with mostly well formed, narrowly ellipsoid, symmetrically tricolpate pollen; ovules 20-30 per fruit. Fruits 1.7-5.5 cm long
x
3.3-4.0 mm wide, reflexed, pendent, occasionally appressed to rachises, often secund, straight to somewhat curved, with undulate edges, glabrous; apical angle of fruit valve 15°-23° (measured from base of style to 5 mm proximate); style persistent, 0.4-1.2 mm in length. Seeds uniseriate, 2.5-5.5
x
1.8-3.5 mm; wing continuous, 0.8-1.5 mm wide.
Distribution, habit and phenology.
Boechera suffrutescens
is distributed north and east of the Great Basin; concentrated in the vicinity of the Snake River Gorge (Hells
Canyon
), but extending from Grant County, Oregon to central Idaho on steep, rocky, basaltic substrates in alpine and subalpine ecozones at elevations from 1800-2500 m; flowering from May-July.
Comments.
Although geographically isolated from the other S2X species of the complex,
B. suffrutescens
s.s. is the least distinct morphologically. The most useful character for distinguishing this species is that individuals usually have basal leaves that are glabrate, with a few 1(-2) rayed trichomes scantily dispersed along the margins and apices. However, plants are occasionally encountered that are pubescent basally with 1-3(-4) rayed trichomes. These individuals often appear stressed or lack flowering stems, suggesting that pubescence may be more prevalent amongst plants growing in unfavourable environments. On the holotype specimen, one of each morphotype is present and the plant lacking a flowering stem is pubescent. All other taxa in the complex are consistently pubescent basally. On robust individuals of
B. suffrutescens
s.s., the basal leaves are generally narrower and the fruits are generally wider than those of the other S2X taxa.
Specimens examined.
Idaho.
Adams County
:
Confluence of Wildhorse River
and
No Business Cr. On N
& W exposures,
13 May 1987
,
D. Atwood
12561
(GH).
Valley County
:
In
basaltic outcrop on E side of high ridge
W of Cascade. Payette
NF,
15 Jul 1937
,
R.C. Rollins
13852
(UC).
Wash County
:
Seven Devils Mts.
,
10 Jul 1899
,
M.E. Jones
6164
A, B (
RSA
).
Washington County
:
Middle
slopes of
Hitt Mountain
,
15 Jun 1943
,
C.H. Christ
14044
(OSC);
Dry
hillside above
Spring Creek
. Ida Range
5
W Twsp.
14
North
,
22 Jun 1940
,
R.J Davis
2184
A, B, C (GH).
Oregon.
Grant County
:
West
rim of
High
Lake Basin
,
Blue Mts.
,
4 Aug 1946
,
B. Maguire
26497
(UC).
Union
(
Baker
/
Wallowa
)
County
:
Bluffs of Snake River
and vicinity, 1881,
W.C. Cusick
919
(GH);
Stony
hills near
Snake River
,
26 May 1898
,
W.C. Cusick
1808
(UC);
Overlooking Hells Canyon
from west.
Northeast of
Hells Canyon Overlook. E
+/- 100 yards from NFD 490.
Take
unpaved NFD 490 NE +/-
3mi
from
Wollawa
Mountain Loop
,
22 Jun 2012
,
D.P. Morin
10
A, B, C, D (NMC), E, F (DUKE); ESE facing slope 1/
4 mi
NE from dirt
Hat Point Road
on E side of
Saddle Creek
Campsite. Overlooks
the
Seven Devils Mtns
and
Saddle Creek
to the east, a tributary to
Snake River
,
25 Jun 2012
,
D.P. Morin
11
A (NMC);
Hat Point Road
and
Saddle Creek
Campground. Overlooks
the
Seven Devils Mtns
and
Saddle Creek
Canyon
to the E.,
26 Jun 2012
,
D.P. Morin
12
A, B, C (NMC); ENE facing rocky basalt on W side of
Wallowa
Mountain Loop.
+/-
1.5 mi
N of turnoff to
Lick Creek
Campground.
16.5 air miles
SE of Joseph.
,
25 Jun 2012
,
D.P. Morin
14
A, B, C, D (NMC), E, F, G (DUKE);
Snake
River Canyon
near the mouth of
Battle Cr.
,
12 Jul 1933
,
M.E. Peck
17616
(OSC);
SE of Enterprise
near crest overlooking
McGraw Creek
E of Forest Route
490 ca. 0.25 road mi NE of the parking area at
Hells Canyon Overlook
,
22 Jun 2012
,
M.D. Windham
4110
(DUKE);
SE of Enterprise
on slope above
Lick Creek
along
Wallowa Mountain Loop Rd.
ca. 14.1 road mi W of its junction with
Upper Imnaha Rd.
,
22 Jun 2012
,
M.D. Windham
4132
(DUKE)
.
Figure 9.
Boechera suffrutescens
, Morin, Windham, Allphin 14 (NMC).