Professor Gu Cuizhi and I have come to the Harvard University Herbaria
to work on the English edition of the Flora of China.
Today, you have joined us for this meeting, thus beginning our
collaboration on the Flora. I will speak informally about our
experiences with the original Chinese edition of the Flora (Flora
Reipublicae Popularis Sinica) with Professor T. T. Yü,
and this should serve as a good beginning for our discussions.
First, please let me give a brief account of our
teacher Professor T. T. Yü, a botanist and also a horticulturist,
who unfortunately died in Beijing in July 1986 at the age of 78.
Professor Yü was a senior researcher of the Institute of Botany,
Chinese Academy of Sciences (CAS), and an Academician of the Division
of Biological Sciences (CAS).
In his early youth, Professor Yü became interested
in botany. After he graduated from the Biological Department of
Beijing Normal University, he began his taxonomic work at the
Fan Memorial Institute of Biology in Beijing. During the War,
he worked in Kunming, Yunnan Province. While in Kunming and under
extremely difficult conditions with poor equipment and poor medical
service, Professor Yü was able to collect a great number
of valuable plant specimens, seeds, and seedlings from Sichuan
and Yunnan Provinces. These specimens are preserved at various
herbaria and botanical gardens in China and in many herbaria in
foreign countries, including the Harvard University Herbaria,
the Missouri Botanical Garden,
the Royal Botanical Garden, Kew, and the Royal Botanical Garden,
Edinburgh. Many living plants cultivated from seeds collected
by T. T. Yü were distributed to many botanical institutions
in western countries so that botanists and taxonomists around
the world have been able to study many valuable Chinese plants.
Professor Yü's collections, including many novelties, have
been, and continue to be, very important and useful for the compilation
of the Flora of China.
From 1947 to 1950 Professor Yü continued his
taxonomic and horticultural investigations at the Royal Botanical Garden Kew
and the Royal Botanical Garden Edinburgh.
After his return to China in 1950, together with other botanists
and horticulturists, he established the Beijing Botanical Garden
of the Institute of Botany and became the Garden's first director;
he later became the deputy director of the Institute of Botany.
To conduct research at the botanical garden, he continued his
studies on horticultural plants including fruit trees and ornamental
plants of the rose family and also camellias. Professor Yü's
taxonomic research was wide in scope. He worked particularly on
the Rosaceae, but also had an interest in Begoniaceae and Leguminosae
(Fabaceae). His publications, including articles and monographs
on Rosaceae, contributed greatly to both botany and horticulture.
Professor Yü was the chief editor of the editorial
committee of the Flora Reipublicae Popularis Sinica. At
about the beginning of 1970, Professor Yü began to compile
the Rosaceae for the Flora. He worked in collaboration with Professors
Gu Cuizhi, Li Chaoluan, Kuan Kechien, and myself. In the course
of our studies, we worked very hard. We examined the extensive
literature on the Rosaceae in Chinese and foreign publications.
In addition, we examined all the specimens of Rosaceae housed
in herbaria and botanical gardens in China and borrowed many plant
specimens from other countries. We mainly studied herbarium materials,
but we also observed living plants in the field. Using evidence
from morphology, distribution, and ecology, we investigated the
Rosaceae for a long time and finally published the account, treating
more than 900 species belonging to the four subfamilies and 55
genera, in volumes 36, 37 and 38 of Flora Reipublicae Popularis
Sinicae. The four subfamilies are the Spiraeoideae, Maloideae,
Rosoideae, and Prunoideae (Amygdaloideae).
I would like to give a brief overview of the work
that I have undertaken concerning the subfamily Maloideae and
the other subfamilies of the Rosaceae for the Flora of China.
In Maloideae, I worked on five genera for the English
edition of the Flora of China, i.e., Sorbus (63-65
spp.), Cotoneaster (ca. 60 spp.), Photinia (45 spp.),
Stranvaesia (5 spp.), and Dichotomanthes (1 sp.).
Some problems exist in the above-mentioned genera. For instance,
in the genera Sorbus and Photinia, the generic limits
recognized by different authors have varied greatly so it is has
been difficult to deal with the plants in China without additional
evidence. We have not divided the genus Sorbus into smaller
genera in the Flora of China.
In the genus Cotoneaster, there is the difficult
problem of apomicts. Dr. Klotz discovered and published many microspecies,
some of which are purportedly distributed in SW Yunnan. Based
on morphological disjunctions and distributions, we have dealt
with some species but due to the lack of type specimens, a few
species recognized by Klotz still remain to be addressed.
In the subfamily Spiraeoideae, I studied Spiraea
with Professor T. T. Yü. There are more than 60 species in
this genus. We published a new system for this genus.
In the subfamily Rosoideae, I studied the genus Rubus.
It is one of the largest genera in the Rosaceae, consisting of
more than 750 species worldwide, of which about 200 species have
been recognized in China. The members of this genus are polymorphic,
variable, and very complicated. After detailed analysis and investigation,
we found that this genus evolved from shrubs to herbs. From a
phylogenetic point-of-view, based upon the evolutionary tendency
of morphological features, chromosome numbers of species recorded
in the literature, and the distribution patterns of species, we
revised Focke's system and suggested a new systematic arrangement
of Chinese Rubus. The arrangement of sections is now presented
in a reverse order from Focke's system. In addition, we discovered
many new species and made new combinations.
In the subfamily Prunoideae (Amygdaloideae), the
generic delimitation of the genus Prunus is also in dispute.
The number of genera recognized by different authors has varied.
In the Flora of China, we divided Prunus into six
genera: Amygdalus, Armeniaca, Prunus, Cerasus,
Padus, and Laurocerasus; I personally treated Amygdalus,
Armeniaca, and Laurocerasus.
In recent years, with the assistance of graduate
students, I studied the pollen morphology and leaf anatomy of
the Photinia complex and have published some papers on
these topics.
Now, please allow me to briefly introduce Professor
Gu Cuizhi's work in the Flora of China. Professor Gu worked on
Rosaceae also in collaboration with Professor Yü. She provided
treatments of 22 genera for the Flora. She studies the genera
Sibiraea, Aruncus, Sorbaria, Neillia,
Exochorda, and so on in the subfamily Spiraeoideae. In
the Maloideae, she treated Malus (about 25 spp.), Pyrus
(14 spp.), Crataegus (17 spp.), Eriobotrya (13 spp.),
Chaenomeles (5 spp.), Amelanchier (2 species), and
others. These genera contain many important fruit trees and ornamental
plants. Professor Gu also studies the genus Rosa in the
subfamily Rosoideae. There are approximately 90 species in this
genus, many of which are ornamental plants. Also, she works on
the genera Prunus, Padus, Maddenia, and Prinsepia
in the subfamily Prunoideae. In the course of compiling the Flora
Reipublicae Popularis Sinica with Professor T. T. Yü,
she discovered and published many new species, made new combinations,
and revised the system of classification for the genus Rosa.
Finally, I think that the following two problems
should be discussed regarding Rosaceae for the Flora of China.
1. With regard to the concept of species, we do not
accept the splitter's point of view. For example, in the genus
Cotoneaster Dr. Klotz recognized and published many new
species, bringing the number of species in Cotoneaster
to upwards of 200 "species" of which many represent
agamic complexes. In the course of our taxonomic treatment of
this genus, I found that it has been very difficult or impossible
to detect the characteristics that distinguish the closely related
species determined by Dr. Klotz. The members of the Rosaceae are
highly diverse in morphology and include a great number of economically
important species, including fruit trees and valuable ornamental
plants. If we adopt the splitter's point of view (i.e., a narrow
concept of species) many economically important species cannot
be conveniently and practically used by the people who are involved
in their production. In addition, it is very difficult or impossible
to distinguish these microspecies. Therefore, we accept the concept
of species in an inclusive sense.
2. There is another problem which presents itself
in dealing with the Rosaceae. During the compilation of the Rosaceae
for the Flora of China, our attention was drawn to the
problem of generic delimitation. In the Rosaceae, the problems
of generic limits are always present especially in the subfamily
Maloideae. The genus Sorbus is usually treated by us in
an inclusive sense, in which exist two large groups of plants,
the one group is characterized by simple leaves, and the other
group by compound leaves. Its generic limits have been treated
differently at various times. Some authors (Focke 1888, 1892;
Fernald 1950, and others) reduced the entire genus Sorbus
to Pyrus, but many others have taken an opposing point
of view. Koehne recognized the sister groups of Sorbus
as separate genera, but these sister groups recognized by Koehne
were recognized at subgeneric or sectional level by Kovanda, who
divides the genus Sorbus into five subgenera: Sorbus,
Aucuparia, Aria, Chamaemespilus, and Torminaria.
Recently, some authors have divided Sorbus into three subgenera:
Aria, Chamaemespilus, and Torminaria.
As mentioned above, the generic limits of Sorbus
have been repeatedly disputed to the present. In China we have
not found sufficient evidence to support dividing the entire genus
into several genera, so we have continued to use the genus Sorbus
in an inclusive sense in the Flora of China.
With regard to the genera Photinia and Stranvaesia, traditionally Stranvaesia has been separated from Photinia according to the number of carpels and by the dehiscence of the fruits. Some authors have reduced the genus Stranvaesia to Photinia. In the Flora of China, we treat them as two separate genera. The problem of generic limits also exists in the genus Photinia. Recently, some authors have separated the caducous-leaved section as a distinct genus; how to deal with it in the Flora of China remains to be solved.
11 January 1997