Bowl Clover, Cup Clover, Wide-collared Clover
Trifolium cyathiferum
This photo shows a close-up view of the involucral bracts of cup clover
as seen in the riparian area of the drained Howard Prairie Lake at Grizzly Creek Campground, Jackson County Parks, OR......July 23, 2021. Note the glabrous
involucre subtending the head of flowers. The involucre is deeply cleft and
has deeply spinulose margins. Sorry, I did not get a shot of any leaves!
Photo
at right illustrates the leaf and involucre of cup clover from a plant found
along a small creek on the South Loop Road to Steens Mt. in southeastern Oregon........June
24, 1999.
Characteristics:
Cup clover is an annual clover with ascending
to erect stems from 10-50 cm high. The leaves are ternately compound (3 leaflets)
with long petioles. The individual leaflets are oblanceolate to obcordate
in shape (See photos.) and range from 5-25 mm long.
The flower heads are rounded with 5 to 30 flowers.
The flower heads range form 5-15 mm wide. Individual flowers are white to
yellowish-white, with the corolla barely extending past the calyx. The involucre
below the flower head is widely flared to cup-shaped (hence the common name)
with 6-14 shallow lobes, the margins finely toothed. The seed pod is 2-seeded.
Habitat:
Cup clover may be found in dry sandy soils to
wet meadows within its range.
Range:
Cup clover may be found from British Columbia
south along the eastern side of the Cascade Mts. to California and eastward
to Idaho. It has also been introduced along the Pacific coast from Juneau,
Alaska to Los Angeles, CA.
This photo shows a close-up view of the involucral bracts of cup clover
as seen at a small, vernally moist meadow at about 2800' along Rd K6000 on the
southeastern slopes of Mt. Adams.........July 10, 2005. Note the glabrous
involucre subtending the head of flowers. The involucre is deeply cleft and
has deeply spinulose margins. Sorry, I did not get a shot of any leaves!
Close-up views of an entire plant of cup clover as well as the cup-shaped involucre subtending the flower head of cup clover. Photographed at the trailhead to Canyon Creek in the Klickitat State Wildlife Area of south-central Washington.........May 27, 2009.
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Close-ups of the involucral bracts and flower head of cup clover as seen in a moist ditch along Forest Service Road 16 at Summit Prairie, Malheur National Forest........August 20, 2011.
A close-up image of the involucre at the base of the inflorescence of cup clover as seen along the South Prong Trail #821, Black Canyon Wilderness.......June 16, 2019.
Cup clover as seen in a moist ditch along Forest Service Road 16 at Summit Prairie, Malheur National Forest.........August 20, 2011.
Paul Slichter
