A review of dipterocarps - Center for International Forestry Research

Biogeography and Evolutionary Systematics of Dipterocarpaceae
other families have disappeared.’ Thus we can just ‘resign
ourselves to leave the Dipterocarpaceae s.s. near the
Guttiferae and Ternstroemiaceae (=Theaceae). With the
Malvales or Tiliales they have very little or nothing in
common.’
However, with recent help of molecular techniques
on two species of Dipterocarpoideae (Shorea stipularis,
Anthoshorea section, and S. zeylanica = Doona
zeylanica) (Chase et al. 1993), Dipterocarpaceae are
placed as an outlier in the order of Malvales. Its relations
with Malvales are with Bombacaceae (Bombax),
Tiliaceae (Tilia), Sterculiaceae (Theobroma) and
Malvaceae (Thespesia, Gossypium). This work on
chloroplast plastid gene rbcL1 confirms several major
lineages which correspond well with Dalgren (1975)
taxonomic schemes for Angiosperms.
From the serology studies of John and Kolbe (1980)
and Kolbe and John (1980) the further existence of the
‘Theales’ is not justified if it contains Guttifereae,
Dipterocarpaceae and Ochnaceae.
In other works on DNA (Tsumura et al. 1993,
Wickneswari 1993) parsimony analysis of molecular
data revealed three major groups which resemble
conclusions drawn from the anatomy of cotyledonary
nodes (Maury 1978, Maury-Lechon 1979a,b). These are:
an ancient group comprising Upuna, Cotylelobium,
Vatica (V. odorata which is a Sunaptea), an intermediate
group comprising Dryobalanops and Dipterocarpus,
and an advanced group comprising Shorea, Hopea and
Neobalanocarpus.
Characters Specific to Dipterocarpaceae
Among the numerous characters cited in the literature
there is not a single character shared by all species of
Dipterocarpaceae sensu lato. A detailed study is needed
to verify the flower bud sepals in all species; a semiquincuncial
sepal arrangement is reported in
Pakaraimaea and Monotoideae (Maguire et al. 1977),
while this arrangement is imbricate (=semi-quincuncial)
or valvate in Dipterocarpoideae.
On the contrary three biological characters exist in
all species of Dipterocarpaceae sensu stricto: the stamen
architecture (Kostermans 1985) and the pollen type
(tricolpate grains, exine without endexine: Maury et al.
1975a, b), and the absence of real post-germinative
growth of cotyledons (Maury 1978, Maury-Lechon
1979a, b, Maury-Lechon and Ponge 1979).
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The detailed aspects of stamens were underlined by
Kostermans (1985): Asian Dipterocarpaceae ‘without a
single exception, have short, very much flattened, broadly
(more rarely narrowly) triangular filaments, which
terminate in a very short, thin, cylindrical part, which
continues behind the pollen sacs as a cylindrical, often
differently colored connectival part and often protrudes
beyond the place of insertion of the pollen sacs, giving
the impression of a sporophyllous ‘leaf’ to which the
pollen sacs are attached at the interior surface. The
anthers are actually dorsifixed, but they appear to be
basifixed. It seems that the stamen architecture is one
of the ‘old’ characteristics of Dipterocarpaceae s.s. which
remained immutable (and hence defines the family, cf.
Stebbins, 1974 and Melville 1983).’ (Stebbins, 1974 and
Melville 1983 in Kostermans 1985).
‘In Monotoideae the filaments are very long,
cylindrical, thin, the 2-celled anthers are dorsally
attached, versatile, there is no extension of the filament
behind the pollen sacs and there is no protruding part
(this is sometimes also lacking in Dipterocarpoideae,
but often replaced by this setae). The pollen sacs of
Dipterocarpoideae are separately and rather loosely (not
completely) tied to cylindrical dorsal connectival part;
the 2 or 4 sacs are not much connected, their tips are
free and pointed or very pointed; the tips have no
connective tissue. C. Woon and Hsuan Keng (1979) have
depicted numerous stamens of the Asiatic
Dipterocarpaceae and all have the same form. In the
Monotoideae, on the contrary, the 2 pollen sacs are
united at their apex (not in Marquesia) by a thick,
triangular-ovoid connectival tissue’ (Kostermans 1985).
Further investigation is thus needed in Asian, African and
South American taxa (including the new Colombian taxon
Pseudomonotes) to judge if these differences have been
over-estimated.
Anatomically the presence of wood resin canals and
multiseriate wood rays, also characterise the Asian taxa.
Chemically the presence in the resins of the Asian
dipterocarps of dammaranic triterpenes and
sesquiterpenes, combined with the absence of
monoterpenes is also common to all Asian species
examined by Ourisson’s team (Bisset et al. 1966, 1967,
1971, Diaz and Ourisson 1966, Diaz et al. 1966). The
triterpenes derived from the skeleton ‘epoxyde of
squalene’ (precursor of sterols) constitute a familial
feature for Dipterocarpaceae sensu stricto. The
distribution of the other resin compounds (particularly