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Overview
Trillium kurabayashii, commonly called giant purple wakerobin, is a sessile-flowered rhizomatous herbaceous perennial in the family Melanthiaceae, endemic to the Klamath-Siskiyou region of extreme southwestern Oregon, northwestern California, and the northern Sierra Nevada — among the most botanically diverse regions in North America. First formally described by John Daniel Freeman in 1975, it is one of the largest sessile trilliums in the Pacific Coast flora, with petals 2.5–4 inches (65–105 mm) long in consistently rich, deep purple-red — without the yellow-pigment variation seen in T. chloropetalum. Plants grow 11–17 inches (28–44 cm) tall from thick rhizomes, producing a whorl of three large, broadly ovate bracts 4–7 inches (11–18 cm) long, typically dark green with subtle mottling or nearly unmottled. The sessile flower sits directly on the bract whorl, its deep maroon-purple petals erect, giving the plant an extraordinary visual presence in the woodland garden. A spicy to musty fragrance — sometimes described as fetid with age — distinguishes it from T. chloropetalum. Dormant by midsummer. Only nursery-propagated stock is acceptable — wild collection is harmful and illegal.
Native Range
Endemic to the Klamath-Siskiyou floristic region of extreme southwestern Oregon (Josephine, Curry, and Jackson counties), northwestern California (Del Norte, Humboldt, Trinity, and Siskiyou counties), and the northern Sierra Nevada, growing in moist, humus-rich soils in the understory of mixed-evergreen, Douglas fir, and tanoak forest at low to mid elevations. Native to North America.Suggested Uses
Giant purple wakerobin is one of the most spectacular Pacific Northwest and Klamath-Siskiyou region native wildflowers for the shade garden, producing some of the largest and most richly colored sessile trillium flowers of any species hardy in this region. Exceptional combined with other Siskiyou natives and with shade-tolerant PNW companions: Asarum caudatum, Polystichum munitum, Disporum, and Dicentra formosa. A plant of significant botanical and educational interest for the horticulture classroom. Only nursery-propagated stock is appropriate; wild collection is harmful and illegal.How to Identify
Appearance
Size & Dimensions
Height11" - 1'5"
Width/Spread1' - 1'6"
Reaches mature size in approximately 7 years
Bloom Information
Giant purple wakerobin blooms in early to mid-spring, typically March through April in Pacific Northwest gardens, slightly later at higher elevations in the Siskiyou Mountains. The deep purple-red sessile flowers appear as the plant reaches its full height and persist for three to four weeks. The dramatic combination of large, deep maroon-purple flowers and boldly whorled bracts makes this one of the most visually striking of all spring woodland perennials in the Pacific Northwest. Plants go fully dormant by midsummer — mark positions clearly.Detailed Descriptions
Flower Description
Consistently deep purple-red to maroon; three erect, narrow petals 2.5–4 inches (65–105 mm); no pedicel, directly on bract whorl; spicy-musty fragranceFoliage Description
Three broadly ovate, dark green bracts 4–7 inches (11–18 cm), typically unmarked or subtly mottledGrowing Conditions
Sun Requirements
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight