פסקי עריס - Note that this an עריס is treated differently than a כרם, where a קרחת is sixteen אמות. 

ועוד - Most ראשונים say that this is a טפח; the רמב"ם says it is one tenth of a טפח.

עריס שהוא יוצא עם הכותל - There are several differently interpretation of the case of this משנה, only some of which are covered here.    According to most, the חדוש of this משנה is that even though one may not plant under any part of a beam if a grapevine is growing on, even if the grapevine is growing on a different part of the beam, under certain circumstances a wall is treated more like the גת of פרק ה, משנה ד, and planted can be more readily permitted. 

מתוך הקרן - According to the first פשט given by the מהר"י בן מלכי צדק, also followed by the ר"ש and the רע"ב, the משנה is referring to vines growing from a wall that makes a turn, and to or three grow from one side, and the rest from the other side, of the corner, as shown by the following illustration (the black lines are each a vine):

According to this interpretation, the ת"ק holds that after giving them their workspace of six טפחים, one may plant other species along the rest of the wall, while R' Yose holds that unless the wall has four אמות in each  direction, it is subsumed by the vines (see his opinion by the גת of פרק ה, משנה ד).  The רא"ש says that the case here is one of two walls, parallel to each other, with vines growing on each in the space between them, as so:

According to this פשט, if either wall has less than four אמות not occupied by the vines, than according to R' Yose that wall is subsumed by the vines.

The משנה ראשונה has a completely different understanding.  According to him, the כתל here is a structural wall, part of a house or courtyard (cf. the use of the term גדר in the first משנה of this פרק for a fence or wall that is completely subsumed to the vines).  The vines are hung from ends of boards that, while part of the wall, protrude outside.  He states that the term וכלה is used to connote that no attachments (such as a separate גדר) are made to these protrusions, or else they could be considered as part of an עריס.  According to this, the משנה is telling us that the walls of a house or a courtyard do not become subsumed to vines that are hung from protrusions from those walls.  However he does not explain what exactly R' Yose holds - are his four אמות a measure of the protruding boards, or of the rest of the wall? צ"ע