Pojar and MacKinnon's description of A. acuminatum says "small, deeply-buried, grey-brown, egg-shaped bulb with a fibrous network on the surface . . ." I have a dim memory of hikers tugging it out of a hillside to eat, so it must sometimes grow shallowly. A number of our bulbs do seed themselves in shallow soils that have accumulated on bedrock, so perhaps that was the case. A. crenulatum "on dry rocky outcrops, rock slides and gravelly balds". Hmm - maybe that was what they were eating. A. cernuum was marked during flower and then dug in August by members of various tribes, which suggests they might grow at some depth, though the ones that seed themselves in my yard have bulbs only . ... . ... . pause to run outside with a ruler and trowel . ... . ... 2 cm deep. -- Diane Whitehead Victoria, British Columbia, Canada maritime zone 8 cool mediterranean climate (dry summer, rainy winter - 68 cm annually) sandy soil