The genus Cinnamomum

158 Nguyen Kim Dao
10 7 mm, pink-violet when mature, glabrous, perianth-cup in fruit shallowly
cupuliform, 4 mm long, truncate or slightly dentate and up to 7 mm broad at the
apex (Li and Li, 1998).
Vietnam cassia: a case of misidentification
Cinnamomum loureirii Nees, 1836, Lecomte, 1913, deser. emend. – Laurus cinnamomum
Lour. 1790. non L. (1753). Nhuc que, que Thanh, que quan.
The earlier publications indicated that Vietnam cassia is Cinnamomum loureirii.
This is also considered to be a variety of C. obtusifolium (Roxb.) Nees, occurring
from the central and northern Himalayas, which is also confused with C. japonicum
(Syn. C. pedunculatum Pres.) native to China, Korea and Japan, and with C. sieboldii,
that is widely seen in Japan (Weiss, 1997). But from over 20 years of study on collection
and classification of specimens of Cinnamomum from the north to the south of
Vietnam, we reached the conclusion that the Vietnam cassia is nothing but C.cassia.
This is a case of misrepresentation that has continued for some time. When Loureiro
proclaimed Laurus cinnamomum, his opinion was “Habitat agrestris in altis montibus
cochinchine ad occidenterm versus Laosios”, but the specimens on which Loureiro based his
study could be mislayed or lost. Merrill (1935) was of the opinion that Lecomte
(1913) based his study on specimens of Chinese origin, not specimens of Indochina
origin. Merrill (Allen 1939) assigned the name of species that Loureiro studied
as Cinnamomum cassia Blume. But the opinion of Li (1984) was that the name
Cinnamomum loureirii sensu Lecomte (1913) non Nees (1836) was a synonym of
C. contractum H.W. Li (1978) (see also Chapter 2). The Vietnam government introduced
the name Vietnamese cassia as a standard without reference to regional origin,
correct botanical source or official grades (Weiss, 1997). However, what is mostly
traded are C. cassia. It was also pointed out that C. loureirii is very poorly represented
in Vietnamese or Chinese herbaria, indicating that this is not a very common species.
It is rather difficult to believe that a commonly cultivated/or a popular tree like
Vietnam cassia is represented so rarely in all herbaria. The inevitable conclusion
reached by taxonomists is that C. loureirii is a very rare species and it cannot be the
botanical source for the commercially traded Vietnam cassia. What is currently
grown in Vietnam is C. cassia. But the harvesting–processing practiced in Vietnam is
very much different and this leads to a product that looks distinctly different from
the product from China and, which possibly came to be considered as derived from
another species.
Ecology
The main production areas of cassia cinnamon in China are characterised by mean
daily temperature of about 22 °C and an annual rainfall of 1250 mm in about 135 wet
days. The absolute maximum temperature is about 38 °C and the absolute minimum
is 0 °C. It is grown in southern China at altitudes up to 300 m. North Vietnam has
the same ecological condition as south China. However, South Vietnam is characterised
by a mean daily temperature of about 23.1 °C. The absolute maximum temperature is
about 35.5 °C and the absolute minimum is 17.6 °C. The cassia tree is naturally distributed
in primary dense forests below 800 m altitude. It is a light demanding tree,
slightly shade tolerant when young, preferring cool and wet condition with a mean