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

Summary:
{See also Morels Table.} Morchella importuna is distinguished by regularly laddered, vertically oriented pits and ridges, and urban habitat in landscaping areas, planters, woodchip beds and gardens. Other features include relatively large size; cap that is conic to occasionally ovoid, with vertical ridges and numerous transecting horizontal ridges that create a laddered appearance, the ridges gray becoming dark grayish brown to nearly black, the pits vertically elongated, bald to finely tomentose, and gray to grayish brown, grayish olive or brownish yellow; stem whitish to pale brownish, bald or finely mealy, developing longitudinal ridges and channels; trough between cap and stem that is not deep; and microscopic characters. It is possible that this species will prove to be a synonym of Morchella elata Fries. The description is derived from Kuo(6) except where noted.

M. importuna is found at least in BC, WA, OR, CA, and NV, (Kuo(6)) and QC, France, Spain, and Switzerland, (Richard(1))

Cap:
2-9cm wide at widest point, 3-15cm high (whole fruitbody 6-20cm high), conic or occasionally ovoid; "12-20 primary vertical ridges and numerous transecting horizontal ridges, creating a laddered appearance", the ridges bald or finely tomentose, "pale to dark gray when young, becoming dark grayish brown to nearly black" when mature, "bluntly rounded when young", becoming sharp or eroded when old; pits vertically elongated at all stages, bald or finely tomentose, "opening and deepening with development", "gray to dark gray when immature to grayish brown, grayish olive or brownish yellow at maturity"

Flesh:
0.1-0.3cm in hollow cap, in stem "sometimes chambered or layered"; "whitish to watery tan"

Underside:
cap attached to stem with a trough about 0.2-0.5cm deep and 0.2-0.5cm wide; inner surface of cap whitish, pubescent

Stem:
3-10cm x 2-6cm, "often basally clavate to subclavate", "developing longitudinal ridges and channels with maturity, especially basally"; "whitish to pale brownish"; bald or "finely mealy with whitish granules"

Microscopic:
spores 18-24 x 10-13 microns, elliptic, smooth, contents homogeneous; asci 8-spored, 220-300 x 12-25 microns, cylindric, colorless; paraphyses 150-250 x 7-15 microns, septate, cylindric "with rounded to subclavate, subcapitate, subacute or subfusoid apices", colorless or brownish in 2% KOH; elements on sterile ridges 125-300 x 10-30 microns, septate, "terminal cell cylindrical with rounded apex, subclavate, clavate, subcapitate or subfusiform", colorless or brownish in 2% KOH