The Antirrhineae include about 30 genera with roughly 320 species, of which 150 are in genus
Linaria. The
type genus is
Antirrhinum L. Antirrhineae are probably most closely related to the
turtlehead tribe (
Cheloneae) and/or a large and badly resolved core group of their family including plants as diverse as
water-starworts (
Callitriche),
foxgloves (
Digitalis), and
speedwell (
Veronica).
Subdivision '' As the Antirrhineae have long been considered a distinct group, there has also been a long debate about recognition of distinct subdivisions. In 1909,
Rouy separated the snapdragon-like
subtribe Linarieae from the open-mouthed Anarrhineae and the
monotypic Rhodochitoneae, the latter due to their
petal-like
calyx. By the mid-20th century,
Rothmaler on
morphological grounds identified five subtribes containing 21 genera: •
Anarrhinum group / Anarrhinae / Simbuletinae (
monotypic) •
Gambelia group / Gambeliinae (3 genera) •
Linaria group / Linariinae (11 genera) •
Maurandya group / Maurandyinae (5 genera) – including Rhodochitoneae •
Mohavea group / Mohaveinae (monotypic)
mimics the entirely unrelated asterid Mentzelia involucrata, misleading its pollinator Xeralictus'' beetles, as well as botanists researching Antirrhineae systematics Some 21st-century
phylogenetic analyses indicate some quite different lineages. Mainly, the earlier authors seem to have
overlumped the snapdragon-like forms (including toadflaxes) which actually do not seem to be closely related, while overemphasizing the morphological diversity of the true snapdragon relatives. As early as 1982,
Speta had realized that the typical toadflaxes (including
Nuttallanthus) were a lineage well apart from the snapdragons and similar genera, and established the Antirrhininae for the latter. In 2000, combining
internal transcribed spacer (ITS) and morphological data from 16 genera, Ghebrehiwet
et al confirmed Rothmaler's proposal of a close relationship between the fairly dissimilar-looking
Maurandya and
Rhodochiton and the distinctness of their lineage from the bulk of the subfamily. However, they found the "Linarieae" hard to resolve, but could already tell that
Kickxia should be moved to the Anarrhinae, and
Asarina and
Cymbalaria to the Maurandyinae. In addition,
Mohavea was recognized as a snapdragon relative with extremely modified flowers, refuting a monotypic Mohaveinae. Vargas
et al in 2004 group (3 genera) •
Gambelia group (at least 3 genera) •
Linaria group (1 or 2 genera) •
Maurandya group (at least 6 genera) However, they also noted profound morphological diversity amongst the
Antirrhinum group, in accordance with the proliferation of
segregated genera. Using ITS data from all 29 then-recognized genera, the 2013 study of Fernández-Mazuecos
et al. the other close to
Antirrhinum as part of the
Sairocarpus complex). Given the highly similar datasets and analyses, a
clerical error confusing the two generic names might be suspected, but considering that the 2013 study included two species of each genus which congruently resolved as
sister taxa,
hybrid introgression, or a disparity between
nuclear (ITS) and
chloroplast (ndhF) evolution or some other
divergence seems a more likely cause. The erratic behavior of the two genera was noted by Vargas
et al but not discussed in Fernández-Mazuecos
et al.; adding to the confusion, Ghebrehiwet
et al found a strongly supported
Galvezia fruticosa-
Gambelia speciosa clade excluding
Pseudorontium and
Schweinfurthia and equidistant from the true snapdragons and toadflaxes, entirely in line with Rothmaler's Gambeliinae. Furthermore, several species were historically moved between the two genera without authors noting anything suggesting against a very close relationship between them. Regarding internal
phylogeny, at present, resolution is insufficient. In the more recent studies, the
Chaenorhinum clade is fairly robustly resolved as sister to the true snapdragons, but otherwise not much is clear. Except for the
Antirrhinum-
Chaenorhinum and
Linaria clades, all main lineages have resolved as
basal in one recent study or another, but the proposed interrelationships between the clades/subtribes other than
Antirrhinum-
Chaenorhinum are at most tenuously supported in all of them. As it seems, however, Rothmaler's general concept of an ancestral radiation of basal lineages and a subsequent diversification of the toadflax-snapdragon group was essentially correct, even though he overlumped the latter.
Genera (
Anarrhinum bellidifolium) is not truly a toadflax As of 2013, 29
genera are included in the Antirrhineae. Listed by clade, they are: (
Chaenorhinum origanifolium) • '''
Antirrhinum clade / Mohaveinae''' (disputed) – most formerly in Linariinae •
Acanthorrhinum Rothm. •
Antirrhinum L. •
Howelliella Rothm. – formerly often in
Antirrhinum •
Misopates Raf. – formerly often in
Antirrhinum •
Mohavea A.Gray – formerly often in
Antirrhinum •
Neogaerrhinum Rothm. – formerly often in
Antirrhinum •
Pseudomisopates Güemes •
Sairocarpus D.A.Sutton – formerly often in
Antirrhinum • '''
Chaenorhinum clade''' – newly recognized, formerly in Linariinae •
Albraunia Speta •
Chaenorhinum (DC.) Rchb. •
Holzneria Speta '' • '''
Cymbalaria clade / Maurandyinae''' •
Asarina Mill. •
Cymbalaria Hill •
Holmgrenanthe Elisens – formerly in
Maurandya •
Lophospermum D.Don – formerly in
Maurandya •
Mabrya Elisens •
Maurandya Ortega – including
Epixiphium (Engelm. ex A.Gray) Munz and
Maurandella (A. Gray) Rothm. •
Rhodochiton Zucc. ex Otto & A. Dietr. • '''
Galvezia clade or Gambeliinae''' (disputed) •
Galvezia Dombey ex Juss. (tentatively placed here) •
Gambelia Nutt. (tentatively placed here) •
Pseudorontium (A.Gray) Rothm. – formerly often in
Antirrhinum •
Schweinfurthia A.Braun '' flowering near the
Castillo de San Julián in Spain • '''
Linaria clade / Linariinae'
sensu stricto'' •
Linaria Mill. •
Nuttallanthus D.A.Sutton – formerly often in
Linaria Lafuentea Lag. is a highly distinct Plantaginaceae genus containing a mere two species from the
Strait of Gibraltar region. It is included in the present tribe by
GRIN, whereas other authors have variously allied it with the
foxgloves (
Digitalis) or even united with the equally puzzling
Oreosolen and
Ourisia in a lineage close to the
broomrape Rehmannia as part of the
Scrophulariaceae sensu lato. In the 2013 study as well as in the 2005 Plantaginaceae analysis by Albach
et al. Lafuentea indeed tends to resolve as an additional and
basalmost lineage (subtribe in
Linnean taxonomy) of the Antirrhineae, far from
Digitalis,
Oreosolen,
Ourisia or
Rehmannia; in fact, these five genera are apparently all distinct from each other at least at tribal level (
Oreosolen and
Rehmannia are even outside the Plantaginaceae). However, the results were not unequivocal and support for including
Lafuentea in the Antirrhineae not very robust. Besides, the interrelationships of the Plantaginaceae tribes are also not at all robustly resolved, and some fairly close relatives of the Antirrhineae – such as
Campylanthus or the singular
Hemiphragma – have similarly uncertain positions as
Lafuentea with regard to their presumed closest relatives. Thus, while
Lafuentea seems to be a "
living fossil" from near the origin of the Antirrhineae and is certainly highly useful as an
outgroup in cladistic studies of their internal relations, whether its placement
within this tribe is correct requires further study. ==References==