Cummings reaches his half-century alongside fellow British & Irish Lion Pierre Schoeman, with both forwards selected to start against Los Pumas on Saturday.
The Warriors lock, who made his Scotland debut against France in 2019, partners the vastly experienced Jonny Gray in the second row as he reaches the landmark appearance.
A Glasgow influence runs throughout the starting XV, with seven Warriors selected from the outset.
The back row remains unchanged from Scotland's final Guinness Six Nations fixture in March, with Matt Fagerson and Rory Darge lining up alongside Jack Dempsey. Darge will also serve as vice-captain.
An all-Glasgow Warriors back three has been entrusted with attacking duties, as vice-captain Kyle Steyn and Jamie Dobie start on the wings, while Kyle Rowe continues at full-back. Inside centre Sione Tuipulotu captains the side, with the Warriors skipper partnered in midfield by Northampton Saints' Rory Hutchinson.
Behind the scrum, Ben White starts at scrum-half alongside Tom Jordan at fly-half.
Up front, Schoeman is joined in the front row by Ewan Ashman and Elliot Millar Mills, who recently helped Northampton Saints lift the Gallagher PREM title.
There is further Glasgow representation among the replacements, where hooker Gregor Hiddleston is in line for a Scotland debut after earning his first senior matchday squad selection.
Hiddleston is joined on the bench by Warriors team-mates Rory Sutherland and Zander Fagerson, with the latter poised to win his 82nd Scotland cap should he feature.
Alex Samuel returns to the international fold for the first time since November's victory over Tonga, while Gregor Brown and George Horne are back after recovering from injuries suffered during the closing stages of the BKT United Rugby Championship campaign.
Fergus Burke is included among the replacements a year on from his first Scotland start during the 2025 summer tour, with Darcy Graham completing the matchday 23.
Scotland
15 Kyle Rowe - Glasgow Warriors (17)
14 Kyle Steyn - Glasgow Warriors (33) - Vice Captain
13 Rory Hutchinson - Northampton Saints (11)
12 Sione Tuipulotu - Glasgow Warriors (38) - Captain
11 Jamie Dobie - Glasgow Warriors (19)
10 Tom Jordan - Bristol Bears (17)
9 Ben White - Toulon (36)
1 Pierre Schoeman - Edinburgh Rugby (49)
2 Ewan Ashman - Edinburgh Rugby (35)
3 Elliot Millar Mills - Northampton Saints (14)
4 Jonny Gray - Perpignan (81)
5 Scott Cummings - Glasgow Warriors (49)
6 Matt Fagerson - Glasgow Warriors (64)
7 Rory Darge - Glasgow Warriors (39) - Vice Captain
8 Jack Dempsey - Toshiba Brave Lupus (33)
Substitutes
16 Gregor Hiddleston - Glasgow Warriors (uncapped)
17 Rory Sutherland - Glasgow Warriors (48)
18 Zander Fagerson - Glasgow Warriors (81)
19 Alex Samuel - Glasgow Warriors (3)
20 Gregor Brown - Glasgow Warriors (16)
21 George Horne - Glasgow Warriors (45)
22 Fergus Burke - Saracens (3)
23 Darcy Graham - Edinburgh Rugby (55)