l - CNCFlora

Volume 91, Number 4
2004
Croat
Revision of Dieffenbachia
taken by Bogner and Nicolson (1991) in their mod- chieae with two genera (DieJ7enbachia and Bogern
revision. Grayum (1984, 1990) placed Dieffen- nera) and the tribe Spathicarpeae with eight genera,
bachia in its own tribe and does not disagree with Mangonia, Taccarum, Asterostigma, Gorgonidium,
Bogner and Nicolson about its relative placement Synandrospadix, Gearum, Spathantheum, and
or taxonomic status. However, Grayum substantially Spathicarpa. Their tribe Spathicarpeae differs from
modified the Philodendroideae by including the ge- the tribe Dieffenbachieae in having tuberous stems
nus Calla and thus mandated a change in the name and leaves with reticulate higher-order venation.
of the subfamily to Calloideae Endl. on the basis However, the latter character is also present in
of priority. This group, as defined by Grayum, is Bognera, one of the two genera in their tribe Diefsubstantially
larger than that of Bogner and Nic- fenbachieae. In the Dieffenbachia alliance Dieffenolson's,
with 40 genera arranged in 17 tribes in five bachieae are distinguished from other tribes by
alliances. This contrasts with 18 genera in 7 tribes having anatropous ovules; the primary lateral veins
according to Bogner and Nicolson. The latter sys- forming a single marginal vein but also lacking coltem
closely mirrors Engler's Philodendroideae, ex- lective veins; and, perhaps most importantly, in
cept for the inclusion of new genera and the syn- having the pistillate portion of the spadix completeonymizing
of others since the time of Engler. The ly fused to the spathe. Tribe Dieffenbachieae sensu
size of Grayum's Philodendroideae resulted from Mayo et al. (1997) is distinguished from other tribes
the inclusion of tribes from the subfamilies Aro- of subfamily Philodendroideae by having stamens
ideae Adans., Pothoideae Engl., and Lasioideae connate into synandria, and in having several free
Engl. (Croat, 1990 [1992]).
staminodia associated with the female flowers. Oth-
In recent suprageneric classifications by Mayo et er useful distinguishing features include a conal.
(1997, 1998) all the genera with unisexual flow- stricted spathe partly adnate with the pistillate spaers
were grouped together in the subfamily Aro- dix, terrestrial caulescent habit, closely parallel
ideae and further divided into non-ranked groups, primary and minor veins, and seeds with endothe
perigoniate Aroideae and aperigoniate Aro- sperm.
ideae. Dieffenbachia, in the latter group, was placed The Dieffenbachia alliance of Mayo et al (1997)
in the Dieffenbachia alliance, one of four alliances has been supported by molecular studies with chlo-
(the others called Philodendron, Schismatoglottis, roplast trnI,-F genes (Barabe; Tam et al, 2004)
and Caladium alliances respectively). These alli- This study shows close relationships between
ances comprise 33 genera with an additional 37 Spathicarpeae and Dieffenbachieae with Dieffengenera
being placed in a group labeled "No alli- bachia being paired with Spathicarpa on one
ance." The classification by Mayo et al. was able branch and with Cerce.sti.s Schott, Rhektophyllum N.
to make use of the results of the recently completed E. Br., and Culcasia P. Beauv. forming another
chloroplast DNA studies and anatomical studies of branch of the tree.
French and colleagues (1995, 1997). DieJ7enbachia, Although both Grayum (1984, 1990) and Bogner
along with Bognera, was placed in the tribe Dief- and Nicolson (1991) placed Dieffenbachia in its
fenbachieae, a tribe characterized by having the own tribe, the authors of both systems now agree
pistillate flowers completely adnate to the spathe. that Bognera, another Neotropical genus, is very
In the most recent suprageneric classification of close to or within the tribe Dieffenbachieae, sensu
the family by Keating (2002, 2003a) Dieffienbachia Mayo et al. (1997). Keating (2002, 2003a) simply
is included in subfamily Philodendroideae, tribe subsumed this tribe (or its genera) within his larger
Spathicarpeae Schott, along with Bognera, Spa- Spathicarpeae, still in essential agreernent.
thantheum Schott, Gorgonidium Schott, Synandros- The subfamily Philodendroideae is worldwide in
padix Engl., Gearum N. E. Br., Spathicarpa Hook., distribution and, sensu Grayum (pers. comm.), it is
Asterostigma Fisch. & C. A. Mey., Mangonia somewhat equally divided between the Old World
Schott, and Taccarum Brongn. ex Schott. Keating's and the New World, with 19 genera (17 of them
revision makes use of a wealth of vegetative ana- endemic) and 761 species in the New World and
tomical information he has accumulated on the 23 (21 endemic) genera and 354 species in the Old
family. All members of the Spathicarpeae share in World. Grayum places the Dieffenbachieae in his
common Type B collenchyma; vascular bundle type Aglaonema alliance with Zantedeschieae Engl.
II (or occasionally types I or III); and either lack (Zantedeschia Spreng.), Aglaonemateae Engl.
laticifers or have non-anastomosing type laticifers. (Aglaonema Schott, Aglaodorum Schott), Spathicar-
The Dieffenbachia alliance of Mayo et al. (1997) peae (Mangonia, Asterostigma, Synandrospadix,
is distinguished by having simple laticifers and free Taccarum, Gorgonidium, Gearum, Spathanthemum,
synandria. It contains two tribes, the Dieffenba- Spathicarpa), and Bognereae S. Mayo & D. Nicol-
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