Euthenia and Demeter
Euthenia was the Greek/Egyptian goddess who could be compared to Abundantia (wikipedia) or Annona (wikipedia) on Roman coins. Demeter (wikipedia) was the Greek goddess of grain and fertility compared to Ceres (wikipedia) the goddess of growing plants and motherly love on Roman coins. Euthenia appears to be a more specific goddess and concept than that of Demeter (Ceres). Euthenia was directly related to the growing of the grain as the fruit of the union with the river god. Both type of goddesses are generally shown with corn-ears, however Demeter is generally shown also holding a torch or scepter while Euthenia's other attribute that she holds is a cornucopia. Roman Abundantia was the personification of good fortune, luck and abundance as well as the guardian of the cornucopia. Roman Annona was the personification of the annual produce and was usually shown with a cornucopia and a ships prow, rudder or anchor symbolizing the transport of the grain over the sea. Note that corn-ears refers to wheat, barley or other old world grain rather than the new world grain of maize which the United States and some of the other countries from the western hemisphere call corn. Corn is used as the name for the most popular grain crop of a country. A civic Tyche reverse can have corn-ears depicted as well. Another good page on corn-ears.
Euthenia:
"Euthenia was a very late addition to the Egyptian pantheon. Originally the personification of "abundance" or "plenty," and represented on the regular coins of Rome as Abundantia, she became the consort of Nilus, during Ptolemaic times, and acquired the status of an important goddess. She was often assimilated to Isis." www.coinsofromanegypt.org
On the Alexandrian coins, Euthenia was often reclining similar to the River god style of coinage.
"Early Greco-Roman representations of Earth, Ge, or Gaia were closely associated with the iconographic type of Demeter (Ceres), a goddess who goverend the fuits of the earth, a mother-goddess, whose most important aspect was fertility. ... is the iconographic type of Euthenia, a roman-period variation of Earth's imagry specifically meant as a personification of abundance... Euthenia was conceived as a counter-part to the reclining river-god. Euthenia's primary function, like Earth's, was to produce the fruits of the earth by her union with the Nile." Late Antique Egyptian Funerary Sculpture: Images for This, By Thelma K. Thomas
Euthenia example of Elagabalus from Markianopolis (Marcianopolis):
Obverse: ΑΥΤ Κ Μ ΑΥΡΗ ΑΝΤΩΝEΙΝΟC ΑΓ (AYT K M AYPH ANTwNEINOC Ag) (Ayt k m ayph antVneinoc aG) with laureate head right. The ΑΓ (Ag) (aG) is a ligature.
Reverse: ΥΠ ΙOYΛ ΑΝΤ CEΛEΥΚΟY ΜΑΡΚΙΑΝΟΠΟ ΛΙΤΩΝ (Yp IOYL ANT CELEYKOY MAPKIANOpO LITwN) (yP ioyL ant ceLeykoy mapkianoPoLitVn) Euthenia (Abundantia or Annona) standing, holding corn-ears and cornucopiae. Euthenia was the spirit of prosperity, abundance and plenty. She was one of the four younger graces. Euthenia is depicted rather than Demeter as Demeter's usual attribute along with corn-ears were normally either a torch or scepter/staff. It was minted under Legate (Governor) Julius Antonius Seleucus between 218 and 222 AD. The diameter is 27 mm and is 11.30 g, die axis 180 deg. Reference: Moush-621. Varbanov-1568v v for different obverse legend, AMNG vol. I, page 260, no. 860 (7 specimen listed). I don't believe Zhekov/Jekov has a match. According to the index, the closest goddess would probably be Demeter. However In the first example (below) the goddess is holding a branch and torch. In all the following examples in Zhekov/Jekov, she is holding a staff/scepter along with the corn ears.
Possible Euthenia example of Elagabalus from Markianopolis (Marcianopolis):
Obverse: ΑΥΤ Κ Μ ΑΥΡΗΛΙΟC ΑΝΤΩΝEΙΝΟC (AYT K M AYPHLIOC ANTwNEINOC) (Ayt k m ayphLioc antVneinoc) With laureate draped and cuirassed, bust right.
Reverse: ΥΠ ΙOYΛΑΝΤ CEΛE ΥΚΟY ΜΑΡΚΙΑΝΟΠΟΛΙ ΤΩΝ (Yp IOYLANT CELE YKOY MAPKIANOpOLI TwN) (yP ioyLant ceLe ykoy mapkianoPoLi tVn) Goddess with corn-ears or branch raised, holding cornucopia. The diameter is 27 mm and is 8.85 g, die axis 180 deg. Reference: Varbanov 1567 (R3), listed as Eumenea. AMNG I pg 260, 861 listed as goddess with corn-ears or branch raised to the top. Pick refers to the goddess as standing as before and the previous listing listed a cornucopia, though this listing doesn't explicitly list one. Varbanov doesn't list the cornucopia, but often gets the descriptions from Pick, Zhekov/Jekov 6.26.5.1 (R4) possible die match, by Zhekov/Jekov's code, listing as Demeter (Ceres), though it is listed separate before all of the others. It appears here that she is holding the cornucopia at a different angle than normally pictured though Zhekov/Jekov lists it as Torch, short handle (as far as I can tell from the Bulgarian). Moush-627/8 627 is woman with long article of clothing, holding corn-ears and cornucopia while 628 is woman standing, holding corn-ears and branch.
Demeter examples of Elagabalus from Markianopolis (Marcianopolis):
Obverse: ΑΥΤ Κ Μ ΑΥΡΗΛ ΑΝΤΩΝEΙΝΟC (AYT K M AYPHL ANTwNEINOC) (Ayt k m ayphL antVneinoc) with laureate head right.
Reverse: ΥΠ CEΡΓ ΤΙΤΙΑΝ8 ΜΑΡΚΙΑΝΟΠΟΛ ΙΤΩΝ (Yp CEPg TITIAN8 MAPKIANOpOL ITwN)(yP cepG titian8 mapkianoPoL itVn) Demeter (Ceres) standing left, holding corn-ears and resting on long torch (of reeds bound together). It was minted under Legate (Governor) Sergius Titianus in probably 222AD. The diameter is 26 mm and is 9.91 g, die axis 15 deg. Reference: Moush-622(veiled?), Not found in Varbanov nor Zhekov/Jekov nor BMC III-Thrace for this Legate.
Obverse: ΑVΤ Κ Μ ΑVΡ ΑΝΤΩΝEΙΝΟC (AVT K M AVP ANTwNEINOC) (Avt k m avp antVneinoc) with laureate bust right.
Reverse: ΜΑΡΚΙΑΝΟΠΟΛΙΤΩΝ (MAPKIANOpOLITwN) (mapkianoPoLitVn) Demeter (Ceres) standing left, holding corn-ears and resting on long torch. The diameter is 17 mm and is 3.00 g, die axis 0 deg. Reference: Moush-622, Varbanov-1397 (R4), Zhekov/Jekov 6.26.5.2v v for different obverse legend.