(Botany) an association of a fungus and a plant in which the fungus lives within or on the outside of the plant's roots forming a symbiotic or parasitic relationship. See ectotrophic mycorrhiza, endotrophic mycorrhiza. [C19: from myco- + Greek rhiza root]
Medical Definition of POSTERIOR MEDIAN SULCUS. : a shallow groove along the midline of the posterior part of the spinal cord that separates the two posterior funiculi and is the external boundary of the posterior median septum. a shallow groove along the midline of the posterior part of the spinal cord that separates the two posterior funiculi and is the external boundary of the posterior median septum.
A posterior calcaneal spur develops on the back of the heel at the insertion of the Achilles tendon. An inferior calcaneal spur consists of a calcification of the calcaneus, which lies superior to the plantar fascia at the insertion of the plantar fascia.A posterior calcaneal spur is often large and palpable through the skin and may need to be removed as part of the treatment of insertional Achilles tendonitis. posterior calcaneal spur develops on the back of the heel at the insertion of the Achilles tendon. An inferior calcaneal spur consists of a calcification of the calcaneus, which lies superior to the plantar fascia at the insertion of the plantar fascia.