The transmitted headword u(/stinos is an error for (or corruption of) u(/sginon; cf. upsilon 674. And there is an analogous fault in the Suda's three quotations from the Anthology: see next note.
[1] Greek Anthology 6.254.3 (Myrinus); already at theta 239 and tau 27. On this epigram, in which a feminizing old man dedicates his women's clothing articles to Priapus, see Gow and Page vol. I (288-289); vol. II (320-321); and further excerpts at beta 90, pi 122, tau 1106, and phi 163. Gow and Page note (vol. I, 288) that the Suda follows the Anthologia Palatina (AP) here in transmitting u(/stinos. However, they adopt (ibid.) the emendation given by the AP scribe designated C (the Corrector) in reading u(/sginon. The LSJ s.v. u(/sgh (web address 1) identifies the probable source of the crimson dye to be this shrub, the kermes oak (Quercus coccifera). In fact, scale insects of the species Kermes ilicis feed upon this shrub oak, the females of which species produce the red dye; cf. Kritsky and Young (9).