Habit and stem All species
of Hapaline are diminutive to moderate-sized slender
to slightly robust tuberous or stoloniferous, clump-forming terrestrial
herbs. Tuberous-stemmed species often produce slender, cataphyll-encased
stolons that eventually give rise to new tubers.
Leaf blades in Hapaline
are either thin-textured or thick and leathery. They vary in shape
from ovate to hastate. Posterior lobes are present in all species,
although lacking from some individuals of H.
appendiculata Ridl. (see below). The arrangement of the
posterior lobes ranges from being parallel in Hapaline
ellipticifolia C.Y. Wu & H. Li, resulting in an elliptic
leaf blade, to hastate in H. colaniae Gagnep. Hapaline displays
two distinct growth types which are linked to the thickness of the
leaf blades. Species with thin-textured leaf blades (i.e. H.
benthamiana, H. brownii,
H. colaniae, H.
ellipticifolia and H. kerrii)
undergo an annual dormant period. These species occur in areas with
a seasonal climate (e.g. Burma, central and NE Thailand, northern
Peninsular Malaysia, much of Vietnam). New growth is marked by leaf
emergence and abundant flowering. Species with thicker, leathery
leaves, (H. appendiculata
and H. celatrix), do not undergo
a dormant period. They are native to areas with a more-or-less aseasonal
climate (e.g. much of Peninsular Malaysia, Sarawak and Brunei).
These differences, coupled with floral morphology characters, define
what appears to be a natural division into two groups of allied
species: H. appendiculata and H. celatrix and H.
benthamiana, H. brownii H. ellipticifolia, H.
colaniae and H. kerrii. Leaf blade variegation, in the
form of irregular and diffuse silver grey to pale green blotches,
has been reported in H. appendiculata,
H. benthamiana, H.
brownii and H. colaniae.
species have white spathes occasionally tinged green or greyish
pink. The spathe is always divided into two zones with the upper
part flattened and erect to reflexed and the lower part clasping.
The inflorescence is borne on a short to long, green to grey-pink
mottled peduncle. At anthesis the peduncle is more-or-less erect
to nodding. After fertilization it thickens and bends downwards,
bringing the developing fruits to soil level. The spathe persists,
the limb eventually breaking off or rotting away to leave the clasping
lower spathe enclosing the ripening fruit (Fig. 2, G; Fig. 3 J).
The spadix is bisexual with unisexual, naked flowers. The ovary
consists of an ellipsoid, ovoid or bottle-shaped uniloculate, uniovulate
ovary with a single anatropous ovule on the basal end of a parietal
placenta. The positioning of the ovules results in an ovule that
is functionally basal. The staminate flowers are 3-androus and fused
into somewhat scattered to densely aggregated, peltate, synandria.
The connectives are massively enlarged into a mushroom-like structure
with the thecae inserted on the lower margin of the connective apex
and dehiscing by an ovate pore (Fig. 3, G & H; Fig. 5, F & G). The
male and female zones are separated by a few synandrodes. All species
have a further zone of synandrodes situated at the spadix apex.
In H. appendiculata, H.
brownii Hook.f. and H. celatrix
P.C. Boyce the spadix apex is enclosed by a cap formed of fused
synandrodes; in the other species the synandrodes are free. A perfume
has been reported from cultivated specimens of H. kerrii Gagnep.
(Collins s.n. sub. Kerr 19462, K!) and faint but very pleasant perfumes
are detectable from cultivated plants of
H. benthamiana Schott, H. brownii,
H. colaniae and H.
celatrix (Boyce & Hay pers. obs.). No pollination studies
have been undertaken.
known for five species (H. appendiculata,
H. brownii, H. celatrix
and H. colaniae). The berries
are enclosed in the persistent lower spathe remains until maturity
(Fig. 2, G; Fig. 3 J). When ripe the berries are globular to ellipsoid
with slight to rather prominent stigmatic remains. The pericarp
is leathery and the mesocarp sticky. Ripe berries are white and
contain a single seed. The seeds are generally ellipsoid with a
very thin smooth testa and a conspicuous raphe. The embryo is large,
has a conspicuous plumule and lacks endosperm (Seubert 1993: 218
- 219). The ripe infructescence is held at soil level by the thickened
and reflexed peduncle (see above). The method of seed dispersal
occur from Burma to southwestern China (Yunnan) and as far south
as Brunei. Most species are quite rare, usually occurring as scattered
colonies or occasionally individual plants. In Brunei, H.
celatrix occurs as large isolated patches at the edge of
lowland mixed dipterocarp forest. In Thailand, H.
benthamiana occasionally occurs as extensive colonies formed
as the result of its stoloniferous habit.