_Tilmadoche_

SECTION I. PHYSARUM

I. Fructification not stipitate, more or less plasmodiocarpous.

1. Peridium simple.

_a._ Calcareous deposits yellow 1. _P. serpula_

_b._ Calcareous deposits reddish or orange 2. _P. lateritium_

_c._ Calcareous deposits white, peridium rugulose 3. _P. vernum_

2. Peridium double.

_a._ Fructification flatly compressed 4. _P. sinuosum_

_b._ Fructification less compressed, rounded.

i. Outer peridium white 5. _P. bitectum_

ii. Outer peridium brown or brown-tinged 6. _P. bogoriense_

iii. Outer peridium yellow; capillitium yellow 7. _P. alpinum_

II. Fructification of sporangia more or less distinct.

A. Sporangia sessile, globose, ovoid, reniform, etc.

1. Peridium double.

_a._ Sporangia white, peridium testaceous. 8. _P. diderma_

_b._ Sporangia tinged with yellow.

i. Sporangia as if interwoven,
compressed 9. _P. contextum_

ii. Sporangia more nearly free, distinct.

o Spores pale, inner peridium
brittle 10. _P. conglomeratum_

oo Spores spinulose, dark violet 11. _P. mortoni_

_c._ Sporangia brown, dehiscence revolute 12. _P. brunneolum_

2. Peridium simple, calcareous, flaky.

_a._ Sporangia grey, plasmodiocarpous;
spores dusky, 10-12 forms of 3

_b._ Sporangia grey, more or less dense;
spores violet, 6-7 13. _P. cinereum_

_c._ Calcareous deposits yellow or greenish,
spores 7-9 14. _P. virescens_

_d._ Sporangia rusty or reddish brown,
more or less dense 15. _P. rubiginosum_

_e._ Sporangia minute, lignicolous,
the fructification much extended
upon a hypothallus, lime deposit
tawny 16. _P. instratum_

_f._ Sporangia white, depressed, annulate,
sometimes with short stipes 17. _P. megalosporum_

3. Peridium simple, not flaky,
small .2-.3 mm., heaped 18. _P. confertu