Because of its concentration in eastern Brazil on the ancient, eroded Guyana shield and
Atlantic Coastal slopes ranging from Baia to Río Grande do Sul, the section Urospadix is possibly
one of the oldest sections in the genus.
The section is apparently based on 2N = 30, however a number of B chromosomes or
fragments have been reported. The chromosome number for A. harrisii (Grah.) Endl. is
especially confusing with both fragments and B chromosomes being reported. Anthurium
bellum Schott has counts of 2N = 28 and 56 (Bhattacharya, 1977 and Mookerjea, 1955
respectively). Anthurium lucidium Kunth with a chromosome number of ca. 124 is the highest
known chromosome number in Anthurium.
Little information about crossability in this section is currently available.
XII. CARDIOLONCHIUM Schott (Fig. 24-28)
This apparently natural group is relatively
well known horticulturally. It is a medium- sized section characterized
by plants with short stems and short internodes and with peduncles and
petioles which are often striate or ribbed (Fig.
24 & 25). The leaf blades are generally conspicuously velvety
on the upper surface while the tertiary veins on the lower surface are
inconspicuous (Fig. 26 & 27). The
condition on the lower surface results from the epidermal cells which
are raised, sometimes even more or less conical. The velvety species which
have been investigated are also distinct chromosomally,
all having additional B-chromosomes (small chromosomal fragments) in addition
to their regular count of 2N = 30 (Sheffer & Kamemoto, 1976).
Some of the well known examples in this section are A. crystallinum Linden & André,
A. magnificum Linden, A. regale Linden and A. warocqueanum J. Moore. Anthurium
cerrocampanense Croat and A. Rubrinervium (Link) G. Don Schott (Fig. 28) are aberrant
members of section Cardiolonchium lacking velvety leaf blades but having winged petioles and
Species long considered to be members of sect. Cardiolonchium , namely A. clarinervium
and A. leuconeurum Lem. from Mexico may not belong in this section and may indeed belong in a
section of their own. Breeding studies by John Banta in Florida have shown that while these
species readily interbreed with a number of other Mexican species they do not cross with more
typical members of sect. Cardiolonchium . Among Mexican species fruits with viable seed have
been obtained for example between A. yetlense Matuda, once believed to be a typical member of
sect. Belolonchium (Croat, 1983) and A. clarinervium but I now believe that these two species
are more perhaps closely related and belong in the same section.
In general where intrasectional interspecific pollinations have been attempted, the
species of section Cardiolonchium are intercrossable, and numerous reports have been made of
intersectional crosses involving section Cardiolonchium with sections Belolonchium ,
Calomystrium and Semaeophyllium . Hybrids between A. cerrocampanense . A. crystallinum and
A. regale Linden and A. subsignatum Schott (Semaeophyllium ) have been made.