Mishnah Uktzin 1:1: Any part of a fruit that can serve as a handle but does not protect the fruit is both susceptible to impurity and can transfer impurity, but it is not included with the rest of the fruit to be considered for the minimal egg size. If it does protect the fruit, even if it does not serve as a handle it is susceptible to impurity and can transfer impurity and it is counted as part of the minimal egg size. If it neither protects nor serves as a handle it is not susceptible to impurity nor can it transfer impurity.

כֹּל שֶׁהוּא יָד וְלֹא שׁוֹמֵר, מִטַּמֵּא וּמְטַמֵּא וְלֹא מִצְטָרֵף. שׁוֹמֵר, אַף עַל פִּי שֶׁאֵינוֹ יָד, מִטַּמֵּא וּמְטַמֵּא וּמִצְטָרֵף. לֹא שׁוֹמֵר וְלֹא יָד, לֹא מִטַּמֵּא וְלֹא מְטַמֵּא:

Mishnah Uktzin 1:2: "Roots of garlic, onion, and leeks: when they are moist, their stem: whether moist or dry, and the column which is next to the food; the roots of lettuce, radish and turnip [combine for the minimal egg size]," the words of Rabbi Meir. Rabbi Yehudah says, "The big roots of radishes, combine [for the minimal egg size], but its fibers, does not combine [for the minimal egg size]." Roots of mint, rue, field vegetables, garden vegetables which are uprooted to replant, and the stalks of grain, and their husks - Rabbi Elazar says even the cobweb-like waste covering - all of these ar susceptible to impurity and can transfer impurity and combine [for the minimal egg size].

שָׁרְשֵׁי הַשּׁוּם וְהַבְּצָלִים וְהַקַּפְלוֹטוֹת בִּזְמַן שֶׁהֵן לַחִין, וְהַפִּטְמָא שֶׁלָּהֶן בֵּין לַחָה בֵּין יְבֵשָׁה, וְהָעַמּוּד שֶׁהוּא מְכֻוָּן כְּנֶגֶד הָאֹכֶל, שָׁרְשֵׁי הַחֲזָרִים וְהַצְּנוֹן וְהַנָּפוּס, דִּבְרֵי רַבִּי מֵאִיר. רַבִּי יְהוּדָה אוֹמֵר, שֹׁרֶשׁ צְנוֹן גָּדוֹל מִצְטָרֵף, וְהַסִּיב שֶׁלּוֹ, אֵינוֹ מִצְטָרֵף. שָׁרְשֵׁי הַמִּתְנָא וְהַפֵּיגָם וְיַרְקוֹת שָׂדֶה וְיַרְקוֹת גִּנָּה שֶׁעֲקָרָן לְשָׁתְלָן, וְהַשִּׁדְרָה שֶׁל שִׁבֹּלֶת וְהַלְּבוּשׁ שֶׁלָּהּ, רַבִּי אֶלְעָזָר אוֹמֵר, אַף הַסִּיג שֶׁל רְצָפוֹת, הֲרֵי אֵלּוּ מִטַּמְּאִין וּמְטַמְּאִים וּמִצְטָרְפִין: