E-Flora BC: Electronic Atlas of the Flora of British Columbia

Amanita constricta
constricted grisette

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

© Michael Beug  Email the photographer   (Photo ID #15238)

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Distribution of Amanita constricta
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Species Information

Subgenus Vaginatae. Amanita constricta is characterized by a tall slender stature, a brown to brownish gray markedly striate cap, the absence of a partial veil and ring, and the presence of a constricted volva with a flaring upper border. |The concept followed here is that of Tulloss(6), but the original description is given below as well. Tulloss(6) comments, "The original description was based on collections of several different species including A. protecta Tulloss & G. Wright and undescribed taxa. Since there is distinct rusty or ochraceous staining in all parts of A. protecta, this could be the source of the claim that the volva of A. constricta stains. The original description''s statement that the cap of the present species can be gray may also result from inclusion of A. protecta in the original concept of A. constricta....At present, no taxa are known to me that appear particularly closely related to A. constricta." |Lindgren(1) say this name has also been used for several undescribed species in section Vaginatae that have a constricted volva. |The term ''grisette'' refers to Amanitas with tall, slender stature, striate cap margin, and saccate (or constricted saccate) volva, but without a partial veil or annulus. Which of the grisettes occur in the Pacific Northwest is uncertain although they are common as a group. |The volva in A. constricta is firmly attached partway up the stem and flares open at the top, whereas in A. pachycolea, A. ''alba'', A. vaginata, and presumably the fulvous-colored Amanita that resembles A. vaginata differ from A. constricta in that the volva on A. vaginata is attached only at the bottom of the stem. |The Amanita ceciliae group does have a constricted volva like Amanita constricta (see SIMILAR). |There is also a species or group of species designated "NW04" which keys out close to A. pachycolea but has pale tan to light brown to grayish brown cap, and the volva may be constricted. According to D. Miller, pers. comm., the DNA sequence of NW04 is closer to Amanita pachycolea than to Amanita constricta. The current descriptions indicate that NW04 is primarily brownish, causing potential confusion for macroscopic identification.

Tulloss says, "Described originally from California, this species range probably extends into southwestern Canada." A. constricta sensu lato has been reported from WA by O''Dell(1) and Edmonds(1) and collections from BC are deposited at University of British Columbia. Amanita constricta was described from CA.
4-13cm across, oval becoming convex or flat to slightly umbonate; color beneath the veil tissue (if present) gray, or sometimes brownish gray; "smooth or covered with a large patch of white to buff or grayish universal veil tissue which often separates later into several pieces", slightly viscid when moist, conspicuously striate, (Arora), 5-13cm across, convex becoming flat-convex to flat, eventually somewhat umbonate to umbonate, margin decurved [downcurved] at first, soon flat to wavy, slightly uplifted when old; 'gray to brownish gray, "pale mouse gray" to "light drab gray", to "drab" to "hair brown", disc at times as dark as "chaetura black", furrows of striations a paler shade of pileus color', often with inconspicuous, radial, dark streaks, viscid when moist, disc bald or covered with a patch of universal veil tissue, the patch membranous, somewhat fibrillose, typically less than 0.1cm thick, when old often breaking at the edges into smaller plaques, 'colored white to buff to "smoke gray", or sometimes with pale vinaceous shades, bruising salmon color when wetted, slowly returning to white', margin entire becoming rimose [cracked], strongly sulcate [grooved] to tuberculate-striate, striations 0.5-1.5cm long, (Thiers)
fragile, rather thin; white to grayish, (Arora), thin, 0.5-1.7cm thick at disc, thinning toward margin, fragile; gray to drab next to cap surface, white below that, sometimes becoming very faintly pinkish when exposed, especially when young, (Thiers)
"close to crowded, adnate to decurrent by a short hook when young, becoming free; white at first, becoming gray, and drying tan to sordid tan to brownish gray. The gills are moderately broad with the edge usually gray and fibrillose. The short gills are in several ranks", (Tulloss), adnate to decurrent by a short hook when young, becoming free, close to crowded, subgills in several series, gills moderately broad; ''white at first becoming gray, "smoke gray" to "pallid mouse gray" to "pale drab gray" '', edge usually gray; edge fimbriate [fringed], (Thiers)
10-16(20)cm x 0.7-1.7cm at apex, cylindric or widening downward, stuffed becoming hollow, without a ring; white, (Tulloss), 10-16(20)cm x 0.7-1.7cm at top, "equal or tapering downward, not bulbous", stuffed becoming hollow, no ring present; white with gray scales that darken when bruised; silky fibrillose, at the top with longitudinal striations or pruinose resulting from contact with the gills, becoming appressed-fibrillose in lower part, on expansion of the cap the outer layer of stem often rupturing and forming rings of appressed-fibrillose scales, (Thiers), VOLVA "membranous volva soon begins to turn gray and become structurally weaker; although I have never observed this, it is said to bruise reddish or salmon when wet then fade back to its previous coloration" (see also comment in NOTES), (Tulloss, with the words "never observed this" italicized), membranous, tightly adhering and apparently interwoven with surface layer to lower one-third to one-half of the stipe, then developing a flaring free margin resembling an annulus, collapsing with age, white to pale buff or pale yellow, bruising reddish when wet, then fading", (Thiers)
ring absent
not distinctive (Thiers)
not distinctive (Thiers)
Microscopic spores:
spores (7.2)9.5-12.8(19.0) x (6.2)8.2- 11.5(17.8) microns, round to nearly round to broadly elliptic, occasionally elliptic, inamyloid; clamps are probably absent from bases of basidia, (Tulloss), spores 9.6-12.8(14.4) x 8-10.4(11.2) microns, round to nearly round to obovoid, smooth, inamyloid, thin-walled, colorless in KOH, apiculus strongly developed, eccentric; basidia 4-spored, occasionally 1-spored and 2-spored, 56-70(77) x 11-16 microns, clavate, colorless in KOH; pleurocystidia and cheilocystidia not differentiated, margin cells of gills abundant to absent, 30-40 x 15-22 microns, saccate to spheropedunculate, colorless in KOH; clamp connections absent, (Thiers)
Spore deposit:
white (Thiers)

Habitat / Range

associated with Pacific coastal species of oak and arbutus as well as Douglas-fir, (Tulloss), in "coastal forests where it occurs mainly under hardwoods such as coastal oaks and madrones, but it has, on occasion, also been found under Douglas fir", (Thiers, for California), fall

Taxonomic and Nomenclatural Links

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Species References

Tulloss(6) (accessed September 17, 2019), Thiers(5), Arora(1)*, O''Dell(1), Edmonds(1), Lindgren(1), Trudell(4)*, Sept(1)*, AroraPocket*, Tulloss(6)*, Desjardin(6)*, Siegel(2)*, Marrone(1)*

References for the fungi

General References