Trillium albidum

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Trillium albidum
Trillium albidum 2.jpg
Mendocino County, California
Status TNC G4.svg
Apparently Secure  (NatureServe) [1]
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Liliales
Family: Melanthiaceae
Genus: Trillium
Species:
T. albidum
Binomial name
Trillium albidum
Synonyms [3]
T. albidum subsp. parviflorum
    • Trillium parviflorumV.G.Soukup

Trillium albidum is a species of flowering plant in the bunchflower family Melanthiaceae. It is the only trillium characterized by a stalkless white flower. The species is endemic to the western United States, ranging from central California through Oregon to southwestern Washington. In the San Francisco Bay Area, it is often confused with a white-flowered form of Trillium chloropetalum . In northern Oregon and southwestern Washington, it has a smaller, less conspicuous flower.

Contents

Trillium albidum was first described by John Daniel Freeman in 1975. The specific epithet albidum means "white", a reference to the uniformly white flower color of this distinctive species. It is commonly known as the giant white wakerobin or white toadshade. [4] [5]

Description

Trillium albidum is a perennial herbaceous plant that persists by means of underground rhizomes. There are three large leaf-like bracts arranged in a whorl about a scape that rises directly from the rhizome, growing to 22 to 58 cm (8.5 to 23 in) in height. The bracts are sessile and broadly ovate, each 10 to 20 cm (4 to 8 in) long and 12 to 15 cm (4.5 to 6 in) wide. The bracts are green and weakly mottled with brown or dark green spots (which often fade later in the season). [5]

Each stem produces one flower, which is held on top of the bracts. The fragrant flower has three lance-shaped green sepals and three wider white (sometimes pink or purple-tinged) petals measuring 4.8 to 8 cm (2 to 3 in) long and 2.2 to 3 cm (1 to 1 in) wide (although there is a conspicuously small-flowered subspecies as noted in the previous section).

Trillium albidum subsp. albidum and T. albidum subsp. parviflorum are distinguished on the basis of multiple characters: [5] [6] [7]

Trillium albidum subsp. albidumTrillium albidum subsp. parviflorum
DistributionSouth of Corvallis, Oregon North of the Columbia River
Stem countOften several from the same rhizome; large clumps are commonOne (rarely more)
Stem lengthLonger: 22 to 58 cm (8.7 to 22.8 in) longShorter: 17 to 30 cm (6.7 to 11.8 in) long
Leaf mottlingImmaculate to lightly mottledLightly to heavily mottled, less commonly immaculate
Leaf sizeLarger: 10 to 20 cm (3.9 to 7.9 in) long and 12 to 15 cm (4.7 to 5.9 in) wideSmaller: 6.5 to 16 cm (2.6 to 6.3 in) long and 5 to 8 cm (2.0 to 3.1 in) wide
Sepals (fruiting stage)Erect with tips touching or crossed over fruitCupped at fruit base before flaring widely outward
Petal sizeLonger and wider: 4.8 to 8 cm (1.9 to 3.1 in) long and 2.2 to 3 cm (0.9 to 1.2 in) wideShorter and narrower: 2.2 to 4.5 cm (0.9 to 1.8 in) long (rarely longer) and 0.4 to 1 cm (0.2 to 0.4 in) wide
Petal shapeWidest near the middle, narrowing about equally in both directionsNarrow, appearing almost straight-sided
Petal attachmentConstricted strongly at the baseNo noticeable constriction at the base
Fruit colorGreen or purplish greenDark reddish purple or maroon
Fruit surfaceDullGlossy to shiny
Fruit shapeTriangular; more or less prominently ridged top to bottom resulting in a series of planes; taller than wideRound; ridging (if any) confined to the top of the fruit; no indication of planes; wider than tall
ScentStrongly rose (funereal)Lightly bitter or spicy-rank, clove-like

In the region between Corvallis, Oregon and the Columbia River, the species is variable and difficult to identify to subspecies level. The directional arrows in the table above point toward the subspecies that dominates with respect to that character. [7]

Trillium albidum is the only sessile-flowered Trillium species characterized by white flowers. Throughout most of its range, this characteristic is sufficient to identify the species, but in the San Francisco Bay Area where both T. albidum and a white-flowered variety of T. chloropetalum occur, the two species are distinguished by their reproductive organs. The latter has dark purple stamens and carpels while those of T. albidum are almost invariably white or pale green, with occasional purple stain. [8] [9]

This plant has gained the Royal Horticultural Society's Award of Garden Merit. [10] [11]

Taxonomy

Trillium albidum was one of five new species described by John Daniel Freeman in 1975 (the others being T. decipiens , T. foetidissimum , T. kurabayashii , and T. reliquum ). [12] The specific epithet albidum, which means "white", [13] refers to its uniformly white flower. Despite being one of the most distinctive species in subgenus Sessilia, the taxon was treated under the misapplied epithet chloropetalum for almost 75 years. To alleviate the confusion, Freeman gave a completely new treatment of Trillium chloropetalum (Torr.) Howell that dissociated the latter from T. albidum. [14]

The following infraspecific names are accepted by most naming authorities: [15] [3]

The two subspecies are distinguished by overall size as well as the size and shape of the flower petals. In subsp. parviflorum, the scape is just half the length of the typical subspecies while the petals are consistently shorter and narrower.

In 2002, Case described two distinct but related Trillium species, T. albidumJ.D.Freeman and T. parviflorumV.G.Soukup. [5] [6] Some naming authorities still consider both of these species names to be valid [16] while other authorities consider the latter name to be a synonym for T. albidum subsp. parviflorum, [17] [18] in which case the two species originally described by Case become a single species. In any case, there is evidence that T. albidum and T. albidum subsp. parviflorum are less closely related to each other than the latter is to T. luteum, a sessile trillium species native to eastern North America. [19]

Distribution and habitat

Trillium albidum has the widest range of any sessile-flowered trillium in western North America, from central California through Oregon to southwestern Washington. [20] [21] In northern California, its range extends eastward from the Pacific coast through the Klamath Mountains into the Sierra Nevada. The type specimen was collected in Josephine County in southern Oregon. The southern edge of its range overlaps with that of T. chloropetalum in the San Francisco Bay Area. The intermediate populations found in this region may be due to hybridization of the two species. [22] [23]

The typical subspecies Trillium albidum subsp. albidum ranges from northern California to central Oregon while T. albidum subsp. parviflorum is found in northwestern Oregon and southwestern Washington. In the region where the two subspecies overlap, from the Umpqua River north to the Columbia River, there are populations of considerable variation, which complicates identification at the subspecies level based on morphological characters alone. [6] [24] In southwestern Oregon, just north of the California line, there is a population of plants with flowers that are pale yellow or creamy (not white) with no purple pigments whatsoever. Since these plants grow at the higher elevations, flowering is delayed to May or early June. [25] Evidently this taxon has not been named.

Trillium albidum is found in diverse habitats, on the moist slopes of mixed deciduous-coniferous forests, among shrubs and thickets, and along stream banks and river beds. [5]

Ecology

Flowering typically occurs in the spring, from mid March to early May. In California, flowers bloom between February and June. [26]

Like other Trillium species, T. albidum has a one-leaf vegetative stage followed by a three-leaf vegetative (juvenile) stage. After several years of vegetative growth, the plant finally reaches its three-leaf reproductive (flowering) stage. [27] It has an indefinite life span of many years.

Conservation

The global conservation status of Trillium albidum is apparently secure (G4). [1] However, Trillium albidum subsp. parviflorum is globally imperiled (T2). [28]

Related Research Articles

<i>Trillium</i> Genus of flowering plants

Trillium is a genus of about fifty flowering plant species in the family Melanthiaceae. Trillium species are native to temperate regions of North America and Asia, with the greatest diversity of species found in the southern Appalachian Mountains in the southeastern United States.

<i>Trillium chloropetalum</i> Species of flowering plant

Trillium chloropetalum, also known as giant trillium, giant wakerobin, or common trillium, is a species of flowering plant in the family Melanthiaceae. It is endemic to the western U.S. state of California, being especially frequent in and around the San Francisco Bay Area.

<i>Trillium erectum</i> Species of flowering plant

Trillium erectum, the red trillium, also known as wake robin, purple trillium, bethroot, or stinking benjamin, is a species of flowering plant in the family Melanthiaceae. The plant takes its common name "wake robin" by analogy with the European robin, which has a red breast heralding spring. Likewise Trillium erectum is a spring ephemeral whose life-cycle is synchronized with that of the forests in which it lives. It is native to the eastern United States and eastern Canada from northern Georgia to Quebec and New Brunswick.

<i>Pseudotrillium</i> Genus of flowering plants

Pseudotrillium is a monotypic genus of flowering plant in the family Melanthiaceae. Its sole species, Pseudotrillium rivale, is commonly known as the brook wakerobin. It is endemic to the Siskiyou Mountains of southern Oregon and northern California. The Latin specific epithet rivale means “growing by streams”, with reference to a preferred habitat.

<i>Trillium ovatum</i> Species of flowering plant

Trillium ovatum, the Pacific trillium, also known as the western wakerobin, western white trillium, or western trillium, is a species of flowering plant in the family Melanthiaceae. It is found in western North America, from southern British Columbia and the tip of southwestern Alberta to central California, east to Idaho and western Montana. There is an isolated population in northern Colorado and southern Wyoming.

<i>Trillium luteum</i> Species of plant

Trillium luteum, the yellow trillium or yellow wakerobin, is a species of flowering plant in the bunchflower family Melanthiaceae with native populations in the Great Smoky Mountains of the United States and surrounding areas.

<i>Trillium discolor</i> Species of flowering plant

Trillium discolor, the mottled wakerobin, pale yellow trillium, or small yellow toadshade, is a species of flowering plant in the family Melanthiaceae. It is native to areas of the Savannah River drainage system of Georgia, North Carolina and South Carolina such as Steven's Creek Heritage Preserve and Lake Keowee. It is found along moist stream banks in upland woods, on acidic to basic soils.

<i>Trillium cuneatum</i> Species of flowering plant

Trillium cuneatum, the little sweet betsy, also known as whip-poor-will flower, large toadshade, purple toadshade, and bloody butcher, is a species of flowering plant in the family Melanthiaceae. It is native to the southeastern United States but is especially common in a region that extends from southern Kentucky through central Tennessee to northern Alabama. In its native habitat, this perennial plant flowers from early March to late April. It is the largest of the eastern sessile-flowered trilliums.

<i>Trillium sessile</i> Species of flowering plant

Trillium sessile is a species of flowering plant in the bunchflower family Melanthiaceae. The specific epithet sessile means "attached without a distinct stalk", an apparent reference to its stalkless flower. It is commonly known as toadshade or toad trillium. It is also called sessile trillium or sessile-flowered wake-robin,, however it is not the only member of the genus with a sessile flower.

<i>Trillium decipiens</i> Species of flowering plant

Trillium decipiens, also known as Chattahoochee River wakerobin or deceiving trillium, is a spring-flowering perennial plant. It occurs mostly near the Chattahoochee River in Alabama, Florida and Georgia. Scattered populations are found elsewhere in these three states, all within the Atlantic Coastal Plain or Gulf Coastal Plain. Rich deciduous woods of bluffs, ravines, and alluvial land provide its most favored habitat.

<i>Trillium cernuum</i> Species of flowering plant

Trillium cernuum is a species of flowering plant in the bunchflower family Melanthiaceae. The specific epithet cernuum means "drooping, curving forwards, facing downwards", a distinctive habit of its flower. It is commonly called nodding trillium or nodding wakerobin since the flower is invariably found nodding beneath the leaves. It is sometimes referred to as the northern nodding trillium to distinguish from Trillium rugelii, a similar nodding species native to the southern Appalachian Mountains. It is also called the whip-poor-will flower since presumably its bloom coincides with the spring arrival of the migrating bird with the same name.

<i>Trillium lancifolium</i> Species of flowering plant

Trillium lancifolium, the lanceleaf wakerobin, lance-leaved trillium, or narrow-leaved trillium, is a species of plants native to the southeastern United States. It is known to occur in Alabama, Florida, Georgia, Mississippi, South Carolina, and Tennessee. The species is imperiled in Alabama and Florida, and critically imperiled in South Carolina and Tennessee.

<i>Trillium stamineum</i> Species of flowering plant

Trillium stamineum, the twisted trillium, also known as the Blue Ridge wakerobin, is a species of flowering plant in the family Melanthiaceae. It is native to the southeastern United States, in Alabama, Mississippi and Tennessee. Its natural habitat is calcareous woodlands.

<i>Trillium pusillum</i> Species of flowering plant

Trillium pusillum is a species of flowering plant in the family Melanthiaceae known by the common names dwarf trillium, least trillium and dwarf wakerobin. It is native to the southeastern and south-central United States from Oklahoma to Maryland.

<i>Trillium recurvatum</i> Species of plant

Trillium recurvatum, the prairie trillium, toadshade, or bloody butcher, is a species of perennial herbaceous flowering plant in the family Melanthiaceae. It is native to parts of central and eastern United States, where it is found from Iowa south to Texas and east to North Carolina and Pennsylvania. It grows in mesic forests and savannas, often in calcareous soils. It is also known as bloody noses, red trillium, prairie wake-robin, purple trillium, and reflexed trillium, in reference to its reflexed sepals.

<i>Trillium petiolatum</i> Species of flowering plant

Trillium petiolatum, the Idaho trillium, also known as the long-petioled trillium or round-leaved trillium, is a species of flowering plant in the family Melanthiaceae. It is native to the northwestern United States, in Idaho, Oregon, and Washington. The type specimen for this species was gathered by Meriwether Lewis in 1806 along the Clearwater River during the return trip of the Lewis and Clark Expedition.

<i>Trillium angustipetalum</i> Species of flowering plant

Trillium angustipetalum, with the common name is narrowpetal wakerobin, is a species of Trillium, plants which may be included within the Liliaceae or the newer family Melanthiaceae.

<i>Trillium kurabayashii</i> Species of flowering plant

Trillium kurabayashii is a species of flowering plant in the bunchflower family Melanthiaceae. The species is endemic to the western United States, occurring in extreme southwestern Oregon, northwestern California, and the Sierra Nevada of northern California. It was first described by John Daniel Freeman in 1975. The specific epithet kurabayashii honors Masataka Kurabayashi, a Japanese cytologist and population geneticist who first postulated the taxon’s existence. It is commonly known as the giant purple wakerobin, a reference to its conspicuously large, dark purple-red flower, one of the largest of any sessile-flowered trillium.

<i>Trillium maculatum</i> Species of flowering plant

Trillium maculatum, the spotted wakerobin or spotted trillium, is a species of flowering plant in the family Melanthiaceae. It is found only in the eastern United States.

Trillium viride, commonly called the wood wakerobin, is a species of flowering plant in the family Melanthiaceae. It is found in the central United States, in certain parts of Missouri and Illinois. The specific epithet viride means "youthful" or "fresh-green", an apparent reference to the color of the plant's flower petals. For this reason, it is also called the green trillium, not to be confused with other green-flowered trilliums such as T. viridescens and the green form of T. sessile, both of which are found in Missouri.

References

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  2. "Giant White Wakerobin (Trillium albidum)". The IUCN Red List of Threatened Species, Version 2022-2. Retrieved 28 March 2023.
  3. 1 2 "Trillium albidum subsp. parviflorum". Plants of the World Online . Retrieved 12 August 2019.
  4. USDA, NRCS (n.d.). "Trillium albidum". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 6 March 2022.
  5. 1 2 3 4 5 Case Jr., Frederick W. (2002). "Trillium albidum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford. Retrieved 25 March 2022 via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  6. 1 2 3 Case Jr., Frederick W. (2002). "Trillium parviflorum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford. Retrieved 25 March 2022 via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
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  8. Freeman (1975), p. 51.
  9. Case & Case (1997), p. 158.
  10. "Trillium albidum". www.rhs.org. Royal Horticultural Society. Retrieved 5 March 2021.
  11. "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. November 2018. Retrieved 17 August 2019.
  12. Freeman (1975).
  13. Gledhill, David (2008). The Names of Plants (4th ed.). Cambridge University Press. p. 41. ISBN   978-0-521-86645-3.
  14. Freeman (1975), pp. 52–55.
  15. "Trillium albidum subsp. albidum". Plants of the World Online . Retrieved 12 August 2019.
  16. "Trillium". The Plant List . Missouri Botanical Garden. Royal Botanic Gardens, Kew . Retrieved 12 August 2019.{{cite web}}: CS1 maint: others (link)
  17. "Trillium parviflorum". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  18. Chambers, Kenton L.; Meyers, Stephen C. (2011). "Nomenclatural changes for some taxa in the Oregon flora". Journal of the Botanical Research Institute of Texas. 5 (2): 619–623. ISSN   1934-5259.
  19. Farmer, Susan B.; Schilling, Edward E. (October 2002). "Phylogenetic Analyses of Trilliaceae based on Morphological and Molecular Data" (PDF). Systematic Botany. 27 (4): 674–692.
  20. "Trillium albidum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 6 March 2022.
  21. "Trillium albidum". Calflora. Berkeley, California: The Calflora Database. Retrieved 6 March 2022.
  22. Freeman (1975), pp. 53–54.
  23. Case & Case (1997), pp. 160–161.
  24. Bledsoe, Karen E. (1993). Morphological and cytological variation in Trillium albidum Freeman (Liliaceae) (MA). Oregon State University. Retrieved 2019-10-19.
  25. Dusek, Edith (Fall 1980). "Trilliums Western Style" (PDF). Bulletin of the American Rock Garden Society. 38 (4): 157–167. Retrieved 24 March 2022.
  26. McNeal, Dale W.; Ness, Bryan D. (2012). "Trillium albidum". In Jepson Flora Project (ed.). Jepson eFlora. The Jepson Herbarium, University of California, Berkeley . Retrieved 13 August 2019.
  27. Kawano, Shoichi; Ohara, Masashi; Utech, Frederick H. (1992). "Life History Studies on the Genus Trillium (Liliaceae) VI. Life History Characteristics of Three Western North American Species and Their Evolutionary-Ecological Implications" (PDF). Plant Species Biol. 7: 21–36. doi:10.1111/j.1442-1984.1992.tb00239.x . Retrieved 25 October 2019.
  28. "Trillium albidum". NatureServe Explorer. NatureServe. Retrieved 6 March 2022.

Bibliography