Mendocino Humboldt Redwood Company, LLC
Monitoring

Rare Plants

MRC and HRC survey all proposed timber harvesting areas for the occurrence of rare plants and their habitats. This includes a field analysis as well as a review of the California Department of Fish and Game’s California Natural Diversity Database.

Table 1 – Rare and uncommon plant occurrences on MRC forestlands, 1998-2012.

Latin name Common name No. of occurrences No. of quads Estimated no. of plants
Astragalus agnicidus Humboldt milk-vetch 20 10 19,649
Boschniakia hookeri small ground cone 2 2 15
Callitropsis pygmaea pygmy cypress 8 5 48
Campanula californica swamp harebell 15 9 49,658
Coptis laciniata Oregon goldenthreads 11 7 946
Lilium maritimum coast lily 4 4 23
Pinus contorta ssp. Bolanderi Bolander’s beach pine 4 2 27
Piperia candida White-flowered piperia 17 8 642
Pleuropogon hooverianus North coast semaphore grass 6 1 20,762
Sidalcea malachroides maple-leaved checkerbloom 5 5 104
Usnea longissima long-beard lichen 62 11 > 293
Total   154 64 92,167

Table 2 – Rare plant occurrences on HRC forestlands, 1999-2011.

Latin name Common name No. of populations 1 No. of quads Estimated no. of plants
Astragalus agnicidus Humboldt milk-vetch 2 2 13,259
Carex arcta Northern clustered sedge 32 2 45
 Coptis laciniata Oregon goldenthread 1 1 100
Erythronium revolutum / oregonum3 Coast fawn lily / giant fawn lily 23 7 6,993
Gilia capitata ssp. pacifica Pacific gilia 15 7 13,546
Montia howellii Howell’s montia 42 11 300,000 (est.)
Packera bolanderi var. bolanderi Seacoast ragwort 31 7 7,701
Piperia candida White-flowered rein orchid 8 3 513
Sidalcea malvaeflora ssp. patula Siskiyou checkerbloom 9 6 2,947
Total   134 NA 345,245 (est.)

1Populations are defined as groups of the same species separated by at least a quarter-mile from other such known groups, equivalent to the CNDDB definition of “occurrence.”
2
The identity of the plants at one location is in question at this time.
3 HRC botanists have discovered several populations which may contain E. oregonum or may be white forms of E. revolutum. At this time we are not confident in the identification and are reporting these as one taxon.

Table 3 – Uncommon plant occurrences on HRC forestlands, 1999-2011.

Latin name Common name No. of populations 1 No. of quads Estimated no. of plants
Lilium kelloggii Kellogg’s lily 32 6 1,376
Lilium rubescens Redwood lily 17 6 164
Listera cordata Heart-leaved twayblade  86  9  62,592
 Lycopodium clayatum Running-pine 83 11 329
Mitella caulescens Leafy-stemmed mitrewort 44 9 52,672
Pityopus californicus California pinefoot 11 4 39
Pleuropogon refractus Nodding semaphore grass 9 5 310
Ribes roezlii var. amictum Hoary gooseberry 4 3 273
Sidalcea malachroides Maple-leaved checkerbloom 80 12 10,247
Usnea longissima Long-beard lichen 172 15 5,102
Total   538  NA 133,104

1 Populations are defined as groups of the same species separated by at least a quarter-mile from other such known groups, equivalent to the CNDDB definition of “occurrence”.

For information on HRC’s rare plant monitoring results, please see the Humboldt Redwood Company Habitat Conservation Plan (HCP) page in the Plans & Reports section of the website.