Vascular Plants of North Carolina
Account for Mobile Onion - Allium mobilense   Regel
Members of Alliaceae:
Members of Allium with account distribution info or public map:
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Section 5 » Family Alliaceae
DistributionThis taxon was considered a good species by Weakley (2018), though named then as A. mutabile. Most references still consider this as Allium canadense var. mobilense. Weakley (2022) shows it as rare in the NC Piedmont and Mountains, with the overall range north to central NC. SERNEC contains specimen records of this taxon from Chatham and Swain counties. SERNEC also shows collections of the similar A. cuthbertii from Harnett County, though Weakley (2022) considers that this taxon does not range north to NC. The BONAP map shows records from Randolph and Madison counties; an iNaturalist photo from Orange County seems to be in error. It seems highly likely that specimens from these counties all represent the same taxon, and if A. cuthbertii is truly absent from NC, then maybe by default they are A. mobilense. Note that Randolph and Harnett counties (with records reported for A. cuthbertii) surround Chatham County (with a specimen of A. mobilense); surely the same taxon is involved, and as Weakley (2022) indicates that A. mobilense occurs from central NC south, but that A. curthbertii is absent from NC, this website is treating all of these as A. mobilense on the map below. Needless to say, nearly nothing is known about what constitutes A. mobilense in NC and what its range is!

Weakley (2022) gives the overall range of this species as central NC south to northern FL and west to TX.
AbundanceCompletely unknown, but as there seems to be no recent collections, the species is perhaps overlooked simply as canadense. Obviously very rare, but hardly any biologists seem to be familiar with A. mobilense. The NC NHP State Rank of SU (State Undetermined) is appropriate for now; is it still present in NC, and if so, how numerous? At any rate, this website feels that it surely must rate as a Watch List species.
HabitatWeakley (2018) states "Dry woodlands, prairies". One specimen label for "A. canadense var. mobilense" (= A. mobilense) states "Dry oak-pine woods". The Find Me a Cure website states "it grows on moist soils in prairies, calcareous barrens, bluffs, etc." As it seems to be very rare in NC, and as several of the habitats (e.g., prairies and calcareous barrens) listed above have circumneutral soil, it appears that the species may be limited in the state to such high pH soils of mafic glades and barrens and wooded margins.
PhenologyBlooms from mid-April into May, and fruits from late May into June.
IdentificationVery little is known about this taxon/species. Weakley's (2018) key shows it very similar to A. canadense, except that this latter species has the umbel partly or almost entirely composed of bulblets, whereas A. mobilense has the inflorescence composed entirely of flowers. Based on the Alabama plants website, A. mobilense has a dense ball of open flowers, as in A. keeverae, whereas when A. canadense is in bloom, only a few flowers are open at any time. The flowers of A. mobilense are white to pink, and the umbel is erect, as in A. keeverae but not nodding as in A. cernuum. Weakley (2018) separates this species from A. cuthbertii by the shape of the tepals: A. mobilense has acute tepals whereas A. cuthbertii has acuminate tepals. This means that the tepals in the former are somewhat triangular with straight sides, whereas A. cuthbertii has tepals that narrow to a longer apex. If you see an Allium in bloom with an erect umbel, and all open (as opposed to closed) flowers and no bulblets, and growing in the Piedmont or low mountains, then it should be this rare species.
Taxonomic CommentsAs mentioned above, Weakley (2018) and a few other references have elevated this taxon to full species status in recent years. Others retain it as a variety of the common A. canadense, as A. canadense var. mobilense. Weakley (2022) has moved this taxon from A. mutabile to now A. mobilense.

Other Common Name(s)None?
State RankSU
Global RankG5T4T5 [G4G5]
State Status[W7]
US Status
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