Comments: PAT *bǝra; cf. also with *p-: *pǝrǝ-cʷǝ id. > Abkh. a-prǝ́-kʷč̌ / a-pǝ́r-č̌kʷ (Bzyb. a-prǝ́xʷč̌ / á-prǝkʷč̌), Abaz. prǝčʷ (the second part in Abkh. has contaminated with á-kʷč̌ / á-č̌kʷ 'top'). PAK *bǝLá-ca / *pǝLá-ca (Ad. reflects also a variant with -r-: Ad. pǝrāc / bǝrāc 'shaggy').
WC languages reflect numerous variants with variation p/b and r/l. If Osset. barc / barcä 'mane' really goes back to Proto-Iran. *barša- (see Abayev 1, 237; doubts are raised by Osset. -c-), then the forms PAK *bǝráca and PAT *pǝrǝcʷǝ should be regarded as Alanisms; otherwise the direction of loan should be reversed and the WC forms analysed on WC ground (cf. PAT *bǝra and PWC *cǝ / *cʷǝ 'hair').
Abdokov (1983, 73) compares the WC forms with PEC *balV 'wool' (q.v.), which seems phonetically less probable. He also cites Chech. =älla 'hairy' - which is in reality a participle of =āl- 'to grow' and does not belong here at all.