Hosta nigrescens (F. Maekawa 1937/AHS 1993)
|Hosta Library species file||Hosta nigrescens|
|Origin||Japan, northern Honshu. See Map.|
|Habitat||Only known as a cultivated plant in gardens, the occurrence in the wild is subject to further field investigations|
|Japanese name||Kuro Giboshi = black hosta|
|Plant||60–70 cm diameter, 65 cm high (24–28 x 26"). Sprout cataphylls pruinose, blackish grey.|
Petiole 30–50 cm (12–20"), slightly arching but erect,
forming a tall plant, gray pruinose glaucous, green
Leaf 25-30 x 17.5–22.5 cm (10–12 x 7–9"), leaf attitude at petiole angled at joint then ±arcuate spreading, ovate-cordate, transition usually tight and contracted, acuminate tip, rugose in part, ±keeled, no waves in margin; entire plant very pruinose initially, farinose, gray green initially, leaf underside and petioles whitish, leaf upper surface pruinose grayish green, slowly changing to shiny deep green.
11–14 pairs of veins, sunken above, very projected, strigose below.
Scape far exceeding height of plant, to 140 cm (56"),
measured to 180 (200) cm (72 (79)") on mature plants, with
±3 (5) sterile bracts, very straight, erect, upper part
rarely, but occasionally bending, solid, terete, permanently
pruinose, lasting until dehiscence; bracts flat and broad,
thick and fleshy, green or whitish green, developing and
opening in a stellar form as seen from above.
Raceme 30 cm (12"), 15–25 flowers, widely spaced.
Flowers 5 cm long, 3 cm broad (2 x 1.25"), mostly white to white, suffused with very light purple, and barely darker stripes; perianth expanding, funnel-shaped, in the central part dilated, bell-shaped, lobes spreading straightly to ±angled to the axis of perianth, stamens not very superior, equal or slightly shorter than perianth.
Anthers purple anterior and posterior, lighter posterior, approaching bi-color, looks light purple.
|Fertility||Very low pod fertility (almost sterile), low pollen fertility|
|Suitable for containers|
|Special remarks||Very likely most plants present in western collections and gardens are related to H. 'Tenryu' rather than to H. nigrescens|
|In Hosta Mill Collection||Not the real wild species, but a plant from a strain that has been in cultivation for centuries is present (this may account for the low fertility) and H. 'Tenryu', which is considered to be identical by W.G. Schmid.|