The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
27. From the yoni a (new) body (springs).
Then, subsequently to the soul having been in conjunction with a person of generative power, generation takes place, and a body is produced in which the soul can enjoy the fruits of that remainder of works which still attaches to it. This scripture declares in the passage, 'Those whose conduct has been good,' &c. From this, also, it appears that the souls to which a remainder clings, when descending and becoming rice plants, and so on, do not enter into the state of forming the body of those plants with its attendant pleasure and pain, but are 'born as plants' in so far only as they enter into conjunction with them.