Part 29

Spores: egg-shaped, 8-9 × 6-7 µm.

Except for their rather special requirements as to substrate preference, these species have in common small size, rather tough horny stems and cap composed of erect ornamented cells.

Several agarics which grow on cones have also been placed in Marasmius. They are frequent in spring and early summer the fruit-bodies being attached by a very long rooting stem and cord of fluffy hyphae to buried cones in conifers. The biology of these fungi is still unknown, but the cones to which they are attached are always closed yet buried often several inches beneath the surface of the soil. It is yet to be found whether the spores of the agaric infect the cones after they drop or whether the cones fall because they have become infected. How do the cones become so deeply buried? Are squirrels or rodents involved? All the species which grow on cones have brown or tawny caps and yellowish brown stems.

~Strobilurus stephanocystis~ (Hora) Singer has cystidia with rounded heads and grows on pine-cones.

~S. tenacellus~ (Fries) Singer has pointed cystidia and grows on pine-cones.

~S. esculentus~ (Fries) Singer has lance-shaped cystidia and grows on spruce cones.

~Baeospora myosura~ (Fries) Singer is tough and pale-coloured and is similar in general characters to species of Strobilurus, but has amyloid spores and fruits on pine-cones in the autumn.

When discussing the specialised plant-substrates, such as cones, one must mention the small brown-spored, pale buff coloured agaric Tubaria dispersa (Persoon) Singer, or Tubaria autochthona (Berkeley & Broome) Saccardo, which grows on the ground under hawthorns, often in troops in summer and autumn, attached to old hardened hawthorn berries.

(ii) Agarics of Pastures and Meadows

(a) Agarics of rough and hill pastures

~Hygrocybe pratensis~ (Fries) Donk

Butter mushroom

Cap: width 20-80 mm. Stem: width 5-12 mm; length 30-70 mm.

Description:

Cap: convex then expanding to become plano-convex with a broad low umbo, tan, pale russet or even yellowish buff throughout or slightly darker at the centre.

Stem: gradually thickened upwards, similarly coloured to the cap or paler if the cap is dark russet.

Gills: pale buff, deeply decurrent and often connected up at their bases by veins.

Flesh: buff or pale tan, thick and soft in the cap, slightly fibrous in the stem.

Spore-print: white.

Spores: medium-sized, ellipsoid to egg-shaped, hyaline under the microscope, 7-8 × 5 µm in size and not becoming bluish grey in solutions containing iodine.

Marginal and facial cystidia: absent.

Habitat & Distribution: Common in pastures or on heaths from early summer to late autumn.

General Information: A fungus easily recognised by the uniform buff-colour of the stem, cap and gills. As one might expect from the common name it is edible; it is held in high regard by many mushroom-pickers.

Although ‘pratensis’ specifically means fields, reflecting the habitat of the fungus, this and related species can also be found on heaths and pastures often intermixed and forming a most interesting flora. The following are perhaps the most commonly seen:

H. lacma (Fries) Orton & Watling and H. cinerea (Fries) Orton & Watling are similar in stature, but metallic grey in colour except for the persistently yellow stem-base in H. lacma.

H. subradiata (Secretan) Orton & Watling is flesh-coloured or brownish and H. virginea (Fries) Orton & Watling is white.

H. nivea (Fries) Orton & Watling and H. russocoriacea (Berkeley & Miller) Orton & Watling are much smaller, the former white and odourless and the latter off-white with a very strong smell of incense.

Illustrations: F 12^{b}; Hvass 95; LH 77; NB 33²; WD 33³.