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, 2015.

Latin name Common name CRPR No. of occurrences Estimated no. of plants Status
Astragalus agnicidus Humboldt milk-vetch 1B.1 28 15,482 Special Status
Calamagrostis bolanderi Bolander’s reed grass 4.2 8 40,000 Watch List
Campanula californica swamp harebell 1B.2 20 49,508 Special Status
Carex californica California sedge 2B.3 4 5 Special Status
Ceanothus gloriosus var. exaltatus Point Reyes ceanothus 4.3 2 526 Watch List
Coptis laciniata Oregon goldenthread 2B.2 16 4,105 Special Status
Cordylanthus tenuis spp. brunneus serpentine bird’s beak 4.3 1 100 Watch List
Erythronium revolutum coast fawn lily 2B.2 2 90 Special Status
Hesperocyparis pygmaea pygmy cypress 1B.2 8 45 Special Status
Horkelia tenuiloba thin-lobed horkelia 1B.2 2 120 Special Status
Kopsiopsis hookeri small groundcone 1B.2 2 120 Special Status
Lilium maritimum coast lily 1B.1 6 6 Special Status
Lilium rubescens redwood lily 4.2 17 424 Watch List
Listeria cordata heart-leaved twayblade 4.2 1 1 Watch List
Lycopodium clavatum running-pine 4.2 1 3 Watch List
Mitellastra caulescens leafy-stemmed mitrewort 4.2 16 2,500 Watch List
Pinus contorta ssp. Bolanderi Bolander’s beach pine 1B.2 4 27 Special Status
Piperia candida White-flowered rein orchid 1B.2 25 697 Special Status
Pleuropogon hooverianus North coast semaphore grass 1B.1 6 29,802 Special Status
Pleuropogon refractus nodding semaphore grass 4.2 1 75 Watch List
Sidalcea malachroides maple-leaved checkerbloom 4.2 8 100 Watch List
Streptanthus glandulosus ssp. hoffmanii secund jewel-flower 1B.3 1 25 Special Status
Usnea longissima long-beard lichen 4.2 88 NA Watch List
Total 269 143,866

Table 2 – Rare plant occurrences on HRC forestlands, 2015.

Latin name Common name No. of populations 1 No. of quads Estimated no. of plants
Astragalus agnicidus Humboldt milk-vetch 2 1 7,667
Carex arcta Northern clustered sedge 3 2 55
Erythronium revolutum / oregonum2 Coast fawn lily / giant fawn lily 28 10 6,685
Gilia capitata ssp. pacifica Pacific gilia 21 9 14,490
Montia howellii Howell’s montia 40 14 35,570
Packera bolanderi var. bolanderi Seacoast ragwort 36 7 6,966
Piperia candida White-flowered rein orchid 21 7 1,726
Sidalcea malvaeflora ssp. patula Siskiyou checkerbloom 9 6 2,663
Total 160 NA 75,822

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.”
2HRC 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, 2015.

Latin name Common name No. of populations 1 No. of quads Estimated no. of plants
Coptis laciniata Oregon goldenthread 2 1 1,100
Lilium kelloggii Kellogg’s lily 78 8 2,914
Lilium rubescens Redwood lily 27 6 373
Listera cordata Heart-leaved twayblade  107  9 74,782
 Lycopodium clayatum Running-pine 105 11 430
Mitella caulescens Leafy-stemmed mitrewort 49 10 60,372
Pityopus californicus California pinefoot 22 10 89
Pleuropogon refractus Nodding semaphore grass 19 10 1,551
Ribes roezlii var. amictum Hoary gooseberry 4 3 273
Sidalcea malachroides Maple-leaved checkerbloom 90 18 10,159
Usnea longissima Long-beard lichen 181 19 5,156
Total 683  NA 157,199

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.