Rasamanjari 9.11

9.11

sūraṇaṃ tulasīmūlaṃ tāmbūlena tu bhakṣayet /
na muñcati naro vīryamekaikena na saṃśayaḥ //

Elephant-foot yam or tulasī root: one should eat either with betel; / a man does not emit semen from either one alone; of this there is no doubt.