The Grihya Sutras, Part 1 (SBE29), by Hermann Oldenberg, , at sacred-texts.com
1 1. If she does not conceive, he should, after having fasted, under (the Nakshatra) Pushya, lay down (in his house) the root of a white-blooming Simhî plant, and on the fourth day, after (his wife) has bathed, he should in the night-time crush it in water and insert it into her right nostril with (the verse), 'This herb is protecting, overcoming, and powerful. May I, the son of this great (mother), obtain the name of a father!'
291:1 13, 1. I have translated according to the reading of a similar Mantra found in the Atharva-veda (VIII, 2, 6), which no doubt is correct, sahasvatî instead of sarasvatî.