Marius latuit looks like a normalization of word order from the emphatic latuit Marius.
47. CANNAQVE PALVSTRI. Canna palustris is a standard feature of Ovid's marshes; see AA I 554, RA 142, and Met IV 298 & VIII 337. At RA 142 Henderson comments 'Ovid probably means the plant called in this country [Scotland] Reed (Phragmites communis, a grass), which the Italians call canna di palude; smaller than harundo (Arundo donax, the Greek κάννα and Italian canna), it nevertheless often reaches a height of 6 or 7 feet'.
48. MVLTA PVDENDA. The entire sequence of events during Marius' flight to Africa.
50. FACIT R. J. Tarrant. For fidem facere ('induce belief') compare Met VI 565-66 'dat gemitus fictos commentaque funera narrat, / et lacrimae fecere fidem' and Caesar BC II 37 1 'nuntiabantur haec eadem Curioni, sed aliquamdiu fides fieri non poterat: tantam habebat suarum rerum fiduciam'. Ehwald (KB 63) defends FERET (BC), quoting Aen X 792 'si qua fidem tanto est operi latura uetustas', but the true meaning of this line is 'if antiquity can ever win belief for a deed so grand' (Jackson Knight); the idiom cannot be fitted into the present passage with acceptable meaning. HABET, the reading of most manuscripts, does not account for FERET, but is in itself acceptable enough; compare Her XVI 59-60 'ecce pedum pulsu uisa est mihi terra moueri— / uera loquar ueri [Heinsius: uero codd] uix habitura fidem' and Cic Flac 21 'sed fuerint incorruptae litterae domi; nunc uero quam habere auctoritatem aut quam fidem possunt?'.
51. SI QVIS MIHI DICERET. Compare Tr IV viii 43-44 'hoc mihi si Delphi Dodonaque diceret ipsa, / esse uideretur uanus uterque locus'.
52. GETE is read from the manuscripts by Heinsius; the form is the same as at Met X 608 'Hippomene uicto', Fast IV 593 'uictore Gyge', EP II iv 22 'in Aeacide Nestorideque', and EP I viii 6 'dura pharetrato bella mouente Gete [uar Geta]'. All editors but Heinsius print GETAE, but this is contrary to Ovid's usage: compare (to take only a few instances) Ibis 637 'Sarmaticas inter Geticasque sagittas', EP I i 79 'inque locum Scythico uacuum mutabor ab arcu', and EP III v 45 'ipse quidem Getico peream uiolatus ab arcu'. The only apparent exceptions to the rule I have found are Tr IV i 21 'Sinti [Ehwald: inter codd Sintae Iac. Gronouius] nec militis ensem', where the compound expression alters matters somewhat, and Fast V 580 'Parthi [uar Parthis] signa retenta manu', where Partha should probably be read; compare Fast VI 244 'Mauras pertimuere manus [codd: minas Alton]' and EP I iii 59-60 'altera Bistonias pars est sensura sarisas, / altera Sarmatica spicula missa manu'.
Getes is also used as an adjective at xiii 18 'paene poeta Getes'.
53. I BIBE ... ANTICYRA. A hendiadys for 'Go drink all the mind-purging hellebore that grows in Anticyra'.
53. PVRGANTES ... SVCOS. For discussions of elleborus see Theophrastus HP IX 10, Pliny NH XXV 47-61, and Aulus Gellius XVII xv. There were two varieties of the plant, black and white (from the colour of their roots): the former was a laxative, the latter induced vomiting and was thought to sharpen the intellect; compare Val Max VIII vii ext 5, Pliny NH XXV 52, Martianus Capella IV 327, and the other passages cited by Brink at Hor AP 300.
54. ANTICYRA. Three places of this name are known from ancient sources; it is not known which of them Ovid had in mind. One was a city in Locris on the north side of the entrance to the Corinthian Gulf; the second was a city near Mount Oeta (Strabo IX v 10), and the third an island of uncertain location (Pliny NH XXV 52). It is possible that Hor AP 300 'tribus Anticyris caput insanabile' should be taken to mean that all three places were famous for hellebore, but ps-Acron glosses tribus Anticyris as 'tribus ... potionibus [Keller: potus codd] ... aut multo elleboro', which Brink accepts, citing Hor Sat II iii 82-83 'danda est ellebori multo pars maxima auaris; / nescio an Anticyram ratio illis destinet omnem' and Persius IV 16 'Anticyras ... sorbere meracas' for the metonymy, and Petronius 88 4 'Chrysippus, ut ad inuentionem sufficeret, ter elleboro animum detersit' for the number. The last two places at least seem to have been known for their hellebore; compare Pliny NH XXV 49 'plurimum autem nascitur in Oete monte et optimum uno eius loco circa Pyram' and XXV 52 'Drusum quoque apud nos ... constat hoc medicamento liberatum comitiali morbo ['epilepsy'] in Anticyra insula'.