Answers are grounded in this paper and cite their sources.
D. T. MacDougal, J. Dufrenoy; Mycorrhizal Symbiosis in Aplectrum, Corallorhiza and Pinus, Plant Physiology, Volume 19, Issue 3, 1 July 1944, Pages 440–465,
No takes yet. Share an insight, caveat, or question.
MacDougal et al. (1944) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: