If a person is required to recite the Beracha of "Al Ha’mihya" after eating grain products, and he recited the Beracha but mistakenly concluded "Al Ha’aretz Ve’al Ha’perot" instead of "Al Ha’aretz Ve’al Ha’mihya," has he fulfilled his obligation? He recited the Beracha correctly, but in the conclusion, he recited the text that is used when reciting the Beracha for fruits of the seven special species, instead of the text for "Al Ha’mihya" recited after eating grain products. Does this mistake disqualify his Beracha, requiring him to recite a new Beracha, or has he fulfilled his obligation despite the mistake he made in the Beracha’s conclusion?
The answer to this question likely lies in a different question. There is a debate among the Halachic authorities as to whether one fulfills his obligation if, before eating a "Mezonot" food, he mistakenly recites the Beracha of "Boreh Peri Ha’adama" – the Beracha recited over foods that grow from the ground. According to some authorities, one does not fulfill his obligation of "Mezonot" if he recited "Boreh Peri Ha’adama," since a "Mezonot" food does not have the status of a "Peri" ("fruit"). A "Mezonot" food is made from flour, which has been processed from grain, and thus the term "Peri Ha’adama" cannot be applied to this kind of food. Others, however, maintain that although we do not generally use the term "Peri" in reference to grain products, grain does grow from the ground, and therefore the phrase "Peri Ha’adama" can include even "Mezonot" food. According to this view, although certainly one should not recite "Boreh Peri Ha’adama" over grain products, one who mistakenly did recite this Beracha over a "Mezonot" food has fulfilled his obligation. This is the position of the Kaf Ha’haim (Rav Yaakob Haim Sofer, Baghdad-Israel, 1870-1939), in Siman 167 (Se’if 76).
Returning to our original question, then, it would appear that there certainly is basis to validate, after the fact, the erroneous recitation of "Al Ha’aretz Ve’al Ha’perot" in place of "Al Ha’aretz Ve’al Ha’mihya" after eating grain products. According to the view of the Kaf Ha’haim, grain products do, in a sense, qualify as "Perot," and thus if one mistakenly recited "Al Ha’aretz Ve’al Ha’perot" instead of "Al Ha’aretz Ve’al Ha’mihya," he has fulfilled his obligation. This ruling becomes even more compelling when we consider that in this case the individual had recited the proper text of "Al Ha’mihya," and made a mistake only in the Beracha’s conclusion. Certainly, he may rely on the Beracha he recited, despite the mistake, and does not have to repeat the Beracha. Although some authorities disagree with this ruling, we apply here the principle of "Safek Berachot Le’hakel," which means that one does not recite a Beracha in a situation where it is uncertain whether it is warranted. This is the ruling of Rabbi Moshe Halevi (Israel, 1961-2001), in his work Birkat Hashem (vol. 2, p. 259; listen to audio recording for precise citation).
Summary: If a person mistakenly concluded the Beracha of "Al Ha’mihya" with the words "Al Ha’aretz Ve’al Ha’perot" instead of "Al Ha’aretz Ve’al Ha’mihya," he has fulfilled his obligation and does not have to repeat the Beracha.