Trillium kurabayashii

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Trillium kurabayashii
Trillium kurabayashii 03.jpg
Botanischen Garten
Dresden, Germany
Status TNC G3.svg
Vulnerable  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Liliales
Family: Melanthiaceae
Genus: Trillium
Species:
T. kurabayashii
Binomial name
Trillium kurabayashii
Synonyms [2]
T. kurabayashii
    • Trillium kurabayashii f. luteumV.G.Soukup

Trillium kurabayashii is a species of flowering plant in the bunchflower family Melanthiaceae. [2] 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, [3] a reference to its conspicuously large, dark purple-red flower, one of the largest of any sessile-flowered trillium.

Unlike most other authorities, the influential Jepson Manual does not recognize Trillium kurabayashii as a distinct species. This discrepancy has led to widespread confusion regarding the identification and distribution of other purple-flowered trilliums native to California, namely Trillium angustipetalum and Trillium chloropetalum .

Description

Trillium kurabayashii is a perennial herbaceous plant that persists by means of an underground rhizome. Like all trilliums, it has a whorl of three bracts (leaves) and a single trimerous flower with 3  sepals, 3  petals, two whorls of 3  stamens each, and 3  carpels fused into a single ovary with 3  stigmas. [4] Since its flower has no stalk, it belongs to subgenus Sessilia, the sessile-flowered trilliums.

Scape erect, 28–44 cm (11–17 in) long, usually 2.32.5 times as long as the bracts. Bracts sessile, ovate or widely ovate, 11–18 cm (4.3–7.1 in) long, dark green, with tips generally slightly acuminate. Sepals lanceolate, 42–70 mm (1.7–2.8 in) long, diverging, greenish or basally purple. Petals oblanceolate, 65–105 mm (2.6–4.1 in) long, usually 3.34.6 times longer than wide, erect, dark purple (variously referred to as maroon-red, red-purple, purple-red, or lurid purple), underside usually duller than the top. Stamens erect, 16–25 mm (0.63–0.98 in) long; filaments short, dark purple; anther sacs introrse, 14–21 mm (0.55–0.83 in) long, with yellow pollen; connectives prolonged up to 0.5 mm. Carpels approximately 4/5 as tall or equal to the stamens; ovary ovoid, 9–13 mm (0.35–0.51 in) tall, dark purple, a rounded hexagon in cross section; stigmas coarsely subulate, 6–8 mm (0.24–0.31 in) long, erect, dark purple. Flowers have a spicy or musty odor at anthesis, sometimes becoming fetid with age. Fruit dark reddish purple, ovoid to ellipsoid, weakly angled, 20–50 mm (0.79–1.97 in), fleshy. [5] [6] [7]

Trillium kurabayashii has one of the largest flowers of any sessile-flowered trillium. Petals up to 140 mm (5.5 in) long have been recorded. [8]

Similar species

Trillium kurabayashii is often confused with other sessile-flowered trilliums in the western United States, partially due to morphological similarities but also because of long-standing disagreements regarding taxonomy. The following key was published by Freeman in 1975: [9]

Identification Key
Trillium subgenus Sessilia of the western United States
19. Bracts long-petioled, the petioles about one-third to one-half the total length; blades usually elliptic, sometimes nearly circular or reniform; scape reaching only to the soil surface or a few centimeters above
T. petiolatum
19. Bracts sessile or subsessile (short-attenuate); blades usually ovate; scape rising well above the soil surface, usually more than 2 decimeters
20
20. Stamens about twice the length of carpels; flowers with sweet rose-like fragrance
21
21. Anther connective tissue greenish; filaments usually green, sometimes purple; anther dehiscence lateral; gynoecium greenish (rarely with purple stigmas); petals white (rarely purple basally) to pink
T. albidum
21. Androecium and gynoecium purple throughout; anther dehiscence introrse; petals varying from purple to yellow or white
T. chloropetalum
22. Petals varying from bright greenish yellow to bronze or purple
T. c. var chloropetalum
22. Petals varying from white or pink to reddish or garnet-purple
T. c. var. giganteum
20. Stamens only slightly longer than carpels; flowers with musty or fetid odor
23
23. Petals linear, more than 7 (mostly ca. 9) times as long as wide, dark purple; bracts ovate, rounded or blunt, basally attenuate, often shiny underneath
T. angustipetalum
23. Petals oblanceolate, less than 6 (mostly ca. 4.5) times as long as wide, brownish or greenish (lurid) purple; bracts ovate, slightly acuminate, sessile, dull green underneath
T. kurabayashii

The ranges of Trillium kurabayashii and T. albidum overlap but their flowers are very different, so there is little chance of confusion when the plant in question is at flowering stage. On the other hand, the native ranges of T. kurabayashii and T. chloropetalum do not overlap, but in the absence of location data, the two species are often confused since both can (and usually do) have dark purple flowers. To distinguish the two species, the relative length of the stamens is diagnostic: the stamens of T. kurabayashii are about the same length as (or slightly longer than) the carpels, while the stamens of T. chloropetalum are almost twice the length of the carpels. Also, the scape of T. kurabayashii is 2.42.6 times as long as the bracts, while the scape of T. chloropetalum is 3.03.3 as long as the bracts. Finally, the odor emitted by the flower of T. kurabayashii is spicy and may become fetid with age, whereas the flower odor of T. chloropetalum is pleasantly rose-like. [5]

Trillium kurabayashii is distinguished from T. angustipetalum by leaf shape and flower dimensions. The leaves of T. kurabayashii are sessile, usually with acuminate tips, while the leaves of T. angustipetalum have a narrow petiole-like base and tips that are rounded or blunt. On average, the sepals of T. kurabayashii are longer and wider than those of T. angustipetalum. Since the petals of T. angustipetalum are much narrower, the relative dimensions of the petals are dramatically different in each species. The petals of T. kurabayashii and T. angustipetalum have an average length/width ratio of (2.7) 4.5 (5.8) and (6.5) 9.0 (11.0), respectively. [5]

Taxonomy

Trillium kurabayashii was one of five new species of sessile-flowered trilliums described by John Daniel Freeman in 1975 (the others being T. albidum , T. decipiens , T. foetidissimum , and T. reliquum ). [9] The specific epithet kurabayashii honors Masataka Kurabayashi, a Japanese cytologist and population geneticist whose work first suggested the presence of an unrecognized species of sessile-flowered trillium on the West Coast of the United States. [10]

Trillium kurabayashii f. luteumV.G.Soukup is a synonym for Trillium kurabayashiiJ.D.Freeman. [11] This form has yellow or greenish-yellow flowers with little or no purple pigments. It is distinct from the yellow form of Trillium chloropetalum , a taxon whose native range does not overlap with Trillium kurabayashii. [12]

Some authorities, including The Jepson Manual , consider Trillium kurabayashiiJ.D.Freeman to be a synonym for Trillium angustipetalum(Torr.) J.D.Freeman. [13] [14] Most other authorities, including the USDA PLANTS Database, Flora of North America and Plants of the World Online, accept Trillium kurabayashii as a distinct species. [1] [2] [3] [7] [15] [16] This disagreement has led to widespread confusion regarding the identification and distribution of other purple-flowered trilliums native to California. [17] [18]

Distribution and habitat

There are two small disjunct populations of Trillium kurabayashii in the western United States. [5] [6] One population extends along the western slope of the Klamath Mountains from Curry County in extreme southwestern Oregon to Humboldt County in northwestern California. (The type specimen was found at the edge of a logged redwood forest in the town of Klamath in Del Norte County, California.) The other population occurs in the western foothills of the Sierra Nevada, in Placer, Nevada, Yuba, and Butte counties in northern California. Outside of its native range, citizen scientists have observed T. kurabayashii in a handful of counties in California and Oregon. [19]

The native range of Trillium kurabayashii overlaps with that of T. angustipetalum and T. albidum. T. kurabayashii is found along streams at the edges of coastal redwood forests; in rich, moist conifer-hardwood forests; and at the higher elevations, both in forests and in open grassy meadows with scattered oak trees. [7] It grows at elevations of 30–150 m (98–492 ft) along the coast and 300–1,000 m (980–3,280 ft) in the Sierra Nevada. [5]

Ecology

On the West Coast, Trillium kurabayashii flowers from late March to mid-April. Flowering is somewhat later in the Sierra Nevada, from early April to early May. [20] It is winter-hardy in central Michigan gardens, but it emerges so early that it gets damaged by frosts and therefore never thrives in that region. [21]

Uses

A garden plant known in the nursery trade as Trillium sessile var. rubrum was widely bought and sold in the 1950s and 60s. It had sessile flowers with large, dark red, erect petals over strongly mottled, sessile leaves. The availability of this plant was largely due to the efforts of a man named Gilman Keasey of Corvallis, Oregon who grew the plants from seed in great quantities. By 1968 his annual crop of flowering size plants had reached about 15,000. Keasey collected his original three plants in northwestern California in 1947, [22] suggesting that the species was in fact Trillium kurabayashii, the only species of sessile-flowered trillium now known to occur in that region.

Bibliography

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 plant 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 luteum</i> Species of plant

Trillium luteum, the yellow trillium or yellow wakerobin, is a species of flowering plant in the bunchflower family Melanthiaceae. It is a member of the Trillium cuneatum complex, a closely related group of sessile-flowered trilliums. The species is endemic to the southeastern United States, especially in and around the Great Smoky Mountains of eastern Tennessee and western North Carolina.

<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 a member of the Trillium cuneatum complex, a subgroup of the sessile-flowered trilliums. 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 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 foetidissimum</i> Species of flowering plant

Trillium foetidissimum, also known as the Mississippi River wakerobin, stinking trillium, or fetid trillium, is a species of flowering plant in the family Melanthiaceae. It is found along the Louisiana–Mississippi border in a variety of habitats.

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

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.

<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 reliquum</i> Species of flowering plant

Trillium reliquum, the relict trillium, Confederate wakerobin, or Confederate trillium, is a monocotyledon species of the genus Trillium, a perennial, flowering, herbaceous plant of the family Liliaceae. It is found only in the southeastern region of the United States: southeast Alabama and central and west Georgia, with a disjunct population in east Georgia and southwest South Carolina. As a relict species, there are a few remaining groups but it was once more abundant when conditions were different. Significant habitat loss has occurred through clearing of forests for agricultural and pine farm uses.

<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 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 a member of the Trillium cuneatum complex, a closely related group of sessile-flowered trilliums. The species is endemic to the southeastern United States, ranging across Alabama, Georgia, South Carolina, and northern Florida.

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.

Hibbertia echiifolia is a species of flowering plant in the family Dilleniaceae and is endemic to northern Australia. It is a variable shrub with elliptic to lance-shaped or oblong leaves and yellow flowers arranged singly in leaf axils, with twenty-nine to forty-five stamens arranged around the three carpels.

Trillium hibbersonii is a species of flowering plant in the bunchflower family Melanthiaceae. The specific epithet hibbersonii honors the English Canadian surveyor John Arthur Hibberson (1881–1955) who first collected this plant in 1938 on Vancouver Island in British Columbia. Hibberson and his son propagated the trilliums, selling them to buyers in England and other European countries. In 1968, Leonard Wiley coined the Latin name Trillium hibbersonii, a name that has since been used by horticulturists without reservation.

References

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  2. 1 2 3 "Trillium kurabayashiiJ.D.Freeman". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 12 March 2022.
  3. 1 2 USDA, NRCS (n.d.). "Trillium kurabayashii". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 13 March 2022.
  4. Case Jr., Frederick W. (2002). "Trillium". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford: Oxford University Press. Retrieved 29 March 2023 via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  5. 1 2 3 4 5 Freeman (1975), pp. 56–59.
  6. 1 2 Case & Case (1997), pp. 194–197.
  7. 1 2 3 Case Jr., Frederick W. (2002). "Trillium kurabayashii". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford: Oxford University Press. Retrieved 29 March 2023 via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  8. Dusek, Edith (Fall 1980). "Trilliums western style" (PDF). American Rock Garden Society Bulletin. 38 (4): 157–167. Retrieved 24 March 2022.
  9. 1 2 Freeman (1975).
  10. Case & Case (1997), p. 194.
  11. "Trillium kurabayashii f. luteumV.G.Soukup". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 15 March 2022.
  12. Soukup, Victor G. (1982). "New yellow-flowered forms of Trillium (Liliaceae) from the northwestern United States". Phytologia. 50 (4): 290–291. Retrieved 15 March 2022.
  13. McNeal, Dale W.; Ness, Bryan D. (2012). "Trillium angustipetalum". Jepson eFlora. The Jepson Herbarium. Retrieved 13 March 2022.
  14. "Trillium angustipetalum". Calflora. Berkeley, California: The Calflora Database. Retrieved 18 March 2022.
  15. "Trillium kurabayashiiJ.D.Freeman". Oregon Flora. Retrieved 20 March 2022.
  16. "Giant Purple Wakerobin". Encyclopedia of Life. Retrieved 18 March 2022.
  17. "Trillium angustipetalum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 18 March 2022.
  18. "Trillium chloropetalum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014. Retrieved 18 March 2022.
  19. "Observations of Trillium kurabayashii outside of its native range". iNaturalist. Retrieved 15 March 2022.
  20. Freeman (1975), p. 57.
  21. Case & Case (1997), p. 197.
  22. Baggett, James (July 1969). "Trillium chloropetalum giganteum" (PDF). Rock Garden Society Bulletin. 27 (3): 81–82. Retrieved 20 March 2022.