(Ed 22 March 2019: I’ve since found an excellent book on shopping in Ancient Rome by Claire Holleran. Here’s the Google books view of the relevant chapter.)

I’ve been trying to sort out a term from Galen’s pharmacology: a group of people called ‘rhôpopôlai‘ who seem to deal with plants professionally. Not ‘professionally’ like doctor- or florist-professionally, but still in a way that everyone recognizes:

"Once I have added this further point, I will end the discussion of abrotanum. The incredible Pamphilus, although he describes this herb first and even tries to give a description of it from his own experience (so what if he doesn’t do this for any of the herbs that follow), nevertheless makes a terrible error: he thought that this plant is the one the Romans call, 'santonicum'. The fact is, abrotanum differs from santonicum, as Dioscorides very accurately described in book three of De materia medica. Everyone knows this, doctors and rhôpopôlai alike.

τοσόνδε μέντοι προσθεὶς ἔτι περὶ ἀβροτόνου καταπαύσω τὸν λόγον, ὡς ὁ θαυμασιώτατος Πάμφιλος, καίτοι ταύτην πρώτην πόαν γράφων καὶ τάχ' ἂν εἰ μηδενὸς τῶν ἐφεξῆς, ἀλλὰ ταύτης γοῦν ἐθελήσας αὐτόπτης γενέσθαι, ὅμως ἔσφαλται μέγιστα, νομίζων ὑπὸ Ῥωμαίων σαντόνικον ὀνομάζεσθαι τὴν βοτάνην. διαφέρει γὰρ ἀβρότονον σαντονίκου, καθότι καὶ Διοσκουρίδης ἔγραψεν ἐν τῷ τρίτῳ περὶ ὕλης ἀκριβέστατα, καὶ πάντες ἴσασι τοῦτό γε ἰατροὶ καὶ ῥωποπῶλαι.

Galen, Simple Drugs, 6.pr. (11.804 K.)

Galen thinks doctors are expected to know the difference between one kind of artemisia and another (artemisia santonicum and artemisia abrotanum). His expectations for the rhôpopôlai, however, are more relaxed, and he doesn't think he's being controversial in saying this (he mentions this profession five times, he's not too big on them). At the same time he also seems confident that he and his audience are familiar with who these people are. The character of the rhôpopôlês is so well known, so utterly unremarkable, that it can slip in as the punchline of Galen’s trash-talk.

Of course, they aren’t unremarkable anymore. I have no idea what a 'rhôpopôlês' is, what he knows or doesn’t know, where one finds him in town, what he does. The rhôpopôlês is an alien to me. Even after putting together a bunch of texts that talk about him, I’m still not sure I really get the joke.

A 'rhôpopôlês' is probably something like a huckster, hawker, costermonger, street-vendor. (to be honest, I don't know what these guys are either. I have an irrational fear of markets and my imagination is limited to the pedlars on summer sundays at Parc Mont Royal). Literally, it is someone who sells or deals in ῥῶπος. What this means is not totally clear: sometimes, it means a trinket, or small non-perishable good, i.e., something you don’t need a fixed shop to sell; other times it means something much more specific, namely pigments, oils, dyes, perfumes and drugs.

The specification we see in later sources led to some debate about whether this term (and terms like it) implies there was a profession of druggists or pharmacists in Roman antiquity. It probably doesn't; there were ‘root-cutters’, but that’s another story.

“'Rhôpopôlês': a person who sells 'rhôpos’, that is any dry, miscellaneous goods.”

ῥωποπώλης: ὁ τὸν ῥῶπον πωλῶν, ὅ ἐστι ξηρὸς φόρτος καὶ ποικίλος.

Phrynichus, Sophistic Preparations (epitome) Page 107, line 1

“Rhôpos and gelgê: Miscellaneous and small goods. Thus, 'rhôpopôlês' (‘rôpos-seller) and 'gelgopôlê' (gelge-seller).”

ῥῶπος καὶ γέλγη· ὁ ποικίλος καὶ λεπτὸς φόρτος, ὅθεν ῥωποπώλης καὶ γελγοπώλη

Aelius Dionysius, Attic Names, s.v. ῥῶπος (entry 14)

“The Attics say ‘gelgê ' and ' gelgê-seller'; Greeks say 'rhôpos ' and 'rhôpos-seller'.”

γέλγη καὶ γελγοπώλης Ἀττικοί, ῥῶπος καὶ ῥωποπώλης Ἕλληνες.

Moeris, Attic Lexicon, 194,4

“It is said that the first Phoenicians to sail to Tartessos, having brought oil and other nautical rhôpos, came back loaded with so much silver that there was nowhere to keep or put it, but when sailing away from the place they were forced to make everything else which they used out of silver, and even all the anchors, as well.”

Τοὺς πρώτους τῶν Φοινίκων ἐπὶ Ταρτησσὸν πλεύσαντας λέγεται τοσοῦτον ἀργύριον ἀντιφορτίσασθαι, ἔλαιον καὶ ἄλλον ναυτικὸν ῥῶπον εἰσαγαγόντας, ὥστε μηκέτι ἔχειν δύνασθαι μήτε ἐπιδέξασθαι τὸν ἄργυρον, ἀλλ' ἀναγκασθῆναι ἀποπλέοντας ἐκ τῶν τόπων τά τε ἄλλα πάντα ἀργυρᾶ οἷς ἐχρῶντο κατασκευάσασθαι, καὶ δὴ καὶ τὰς ἀγκύρας πάσας.

Pseudo-Aristotle, On Marvellous Things Heard, 844a17-23

“Nature is everywhere precise, artistic, lacking nothing and without excess – ‘having’, as Erasistratus says, ‘nothing rhôpikon.’” (=trashy? tracky? worthless?? superfluous?)

πανταχοῦ μὲν γὰρ ἡ φύσις ἀκριβὴς καὶ φιλότεχνος καὶ ἀνελλιπὴς καὶ ἀπέριττος, ‘οὐδέν’ ὡς ἔφησεν Ἐρασίστρατος ‘ἔχουσα ῥωπικόν’

Plutarch, Moralia 495C7-9 = Erasistratus Fr. 83

[[then there’s a semantic shift, at some point in the dark ages.]]

“'Rhôpos': compounds, pigments, all those things used by dyers, painters and perfumers. Whence, 'rhôpopôlês', 'perfume dealer' (?). Some people have also called miscellaneous goods, 'rhôpos'.”

Ῥῶπος: μίγμα· χρώματα, ὅσα βαφεῦσι, ζωγράφοις, μυρεψοῖς χρησιμεύει· ὅθεν ῥωποπώλης, ὁ μυροπώλης· τινὲς δὲ καὶ τὸν παντοδαπὸν φόρτον, ῥῶπον εἰρήκασιν.

Photius, Lexicon, s.v. Ῥῶπος (p.494)

“Rhôpos: compounds of colour, those which are used by dyers, painters and perfumers. Whence 'rhôpopôlês'. Some people have also called miscellaneous goods 'rhôpos'.”

Ῥῶπος: μίγμα χρώματος, ὅσα βαφεῦσι, ζωγράφοις, μυρεψοῖς χρησιμεύει. ὅθεν ῥωποπώλης. τινὲς δὲ καὶ τὸν παντοδαπὸν φόρτον ῥῶπον εἰρήκασι.

Suda, s.v. Ῥῶπος

“A rhôpos is a small, cheap, miscellaneous good, as Aelius Dionysius says, while gelgê, he says, is what the ancients called it. Whence, just as there are rhôpos-sellers, so too there are gelgê- sellers. The word, 'rhôpos', occurs in Demosthenes and others, and in Strabo. From this also comes rhopoperperethra, when someone calls out to someone they are mocking with vulgarity and silliness ('trash-talk'?), the inflection of which follows daktylethra ('finger sheath') and similar words. It also occurs in the verb, 'rhôpizein', which refers to making compounds and mixtures.

Ῥῶπος μέντοι λεππὸς καὶ εὐτελὴς φόρτος, ὡς δὲ Αἴλιος Διονύσιος λέγει, καὶ ποικίλος, γέλγην δέ, φησίν, αὐτὸν ἔλεγον οἱ παλαιοί. ὅθεν καθὰ ὁ ῥωποπώλης, οὕτω καὶ ὁ γελγοπώλης. ἡ δὲ λέξις τοῦ ῥώπου παρά τε Δημοσθένει καὶ ἑτέροις, κεῖται δὲ καὶ παρὰ τῷ Στράβωνι. ἐκ τούτου δὲ καὶ ῥωποπερπερήθρα τις προσερρήθη ἐπὶ χυδαιότητι καὶ φλυαρίᾳ σκωπτόμενος, οὗ ἡ παραγωγὴ κατὰ τὸ δακτυλήθρα καὶ τὰ ὅμοια. φέρεται δὲ καὶ ῥῆμα τὸ ῥωπίζειν, ὃ δηλοῖ τὸ σύμμικτα καὶ συμπεφυρμένα ποιεῖν.

Eustathius, Commentarii ad Homeri Iliadem, 3.459-360