1.  History of development of the forest flora Since the Cenozoic period, the number of forest tree species has steadily  risen.

In the course of time, some of the archaic types slowly diminished and perished,

and new forms gradually evolved. During the palaeocene, the numher of the gymnospe-

rms (with the exception of conifers) and ferns drastically decreased, and that of con-

ifers, on the contrary, increased significantly, and meantime the broad-leaved tree spe-

cies also appeared. During the Neocene, the angiosperms expanded rapidly and the ve-

getation gradually shifted towards the mixed deciduous-evergreen forest. Shortly before

the Quaternary, there was a series of world-wide climatic fluctuations, as illustrated by

progress and retreat of glaciers, cold-resistant and warm-loving  (thermophilic)  plants

appeared alternately.  In the post-glaciation period, the zonal distribution of forest ve-

getation in Zhejiang Province was essentially similar to that of the present time. Exca-

vations from Homu-tu, Yu-Yao County,  reveal a luxuriant subtropical forest which

existed 7000 years ago.

      2.  Characteristics of the flora and vegetation

      (1)  Of ancient origin, with rich relic elements.

      Archaic gymnosperms such as Ginkgo biloba, Amentotaxus argotaenia, Pseudotaxus

chienii, Torreya jackii, T. grandis, Taxus chinensis var. mairei, Podocarpus macrophyllus,

P. neriifolia, etc, are all found in the Cretaceous deposits.  The occurrence of Ginkgo

can be traced hack to the Triassic. Most of the conifers, however, were found in the Ju-

rassic, and they have remained to the present time as the main elements of the needle-

leaved forests.

     Among the primitive angiosperms, Magnoliaceae is represented by 19 species of 8

genera; Fagaceae and Lauraceae are the dominant evergreen broad-leaved tree species,

the former by 6 genera and 43 species, and the latter by 10 genera and 42 species. Ha-

mamelidaceae is represented by 10 genera and 18 species, while Ulmaceae, Tiliaceae, Elae-

ocarpaceae, by 21 species of 7 genera, 9 species of 2 genera and 6 species of 2 genera

respectively.

      (2)  Rich in species and consisting of diverse geographic elements, but domi-

nated by the tropical ones.

     Throughout Zhejiang Province, there are over 1300 taxa of woody plants (includ-

ing varieties and cultivated ones) belonging to 109 families and 423 genera.  Among

them, 8 families with 25 genera and about 45 species, are gymnosperms, and the rest, 101

families with 398 genera and about 1260 species and varieties, are angiosperms.  The

major angiospermous families include Mognoliaceae,  Fagaceae,  Lauraceae,  Theaceae,

Aquifoliaceae and Bambusoideae.  Dominant families and genera are the tropical ones,

and next in the order, are the East Asiatic, the E. Asia-N. American, then the tempe-

rate, the cosmopolitan, endemic and other elements.

      (3)  Rich in endemic species, in monotypic and oligotypic genera.

      The endemic species include Abies beshanzuensis, Ostrya rehderiana, Carpinus pu-

toensis, Carpinus tientaiensis, Celtis chekiangensis, Calycanthus chinensis, Machilus mi-

nutiloba, M. chekiangensis, Semiliquidambar caudata var. cuspidata, Acer aeutum, A.

yangjuechi, A. Changhwaense, A. elegantulum, A. pauciflorum, Ilex qinyuanensis, Sty-

rax zhejiangensis, Photinia zhejiangensis, Actinidia zhejiangensis, etc.  The monotypic

and oligotypic genera are examplified by Ginkgo, Pseudotaxus, Pseudolarix, Fokienia,

Cyclocarya, Parakmeria, Pteroceltis, Sargentodoxa, Decaisnea, Aphananthe, Hemiptelea,

Zelkova, Fortunearia, Semiliquidambar, Polithyrsis, Ostrya,  Heptacodium,  Tapiscia,

Bretschneidera, Choerospondias, Kalopanax, Halesia, Hovenia, Emmenopterys, Eucom-

mia, Pileostegia, Platycrater, Alniphyllum, etc.  The majority of the species mentioned

above are rare and precious ones.

      (4)  Introduced species gaining importance

     Zhejiang Province is mainly situated in  the mid-subtropical zone, and from Yukuan District and the Wenzhou Prefecture southwards it belongs to the evergreen broad-leaved south subtropical forest belt. A number of south subtropical species, such as Eucalyptus spp., Casuarina spp., Acacia mearnsii, have  been successfully introduced into this region.  The introduction of other species, such as Cinnamomum cassia, Grevillea robusta, Michelia alba, Canarium album, Litchi chinensis, Euphoria longan, Kandelia candel, are successful in certain areas.  Small plantations of introduced species from S. W. China e.e. Cinnamomum glanduliferum, C. septentrionale have been established. In

addition, Metasequoia glyptostroboides, Ulmus pumila, several exotic Pinus species, Carya illinoensis, Robinia pseudoacacia, Amorpha fruficosa, etc. are widely planted throughout Zhejiang Province. In recent years, cold-temperate species such as Chamaecyparis obtusa, Thuja standishii, Thuja occidentalis, Abies firma have been introduced and planted in the mountainous areas.  The forest flora of the province is thus being further enriched.

      3.  Geographical analysis of the forest flora

      (1)  The south part of Zhejiang lies in the transitional belt between the East and

South China Floristic Regions, its east part being on the north margin of the South

China Floristic Region, and its west part on the south margin of the East China Floristic Region.

      (2)  The north part of the province is weakly influenced by the temperate elements, but the influence may extend to the central part of this province as the elevation

there is higher.

      (3)  Diverse floristic elements such as those belonging to Japan, Taiwan (China),

C. China and S. W. China regions also occur in the province, especially in its western

and eastern parts.

Pollen morphology of Chinese 19 species representing 6 genera in the tribe

Zizipheae Brongn., Rhamnaceae, was examined under light microscope and scanning electron microscope. The pollen grains oblate or suboblate, rarely subspheroidal.   Polar axis 13.1-26.1μm long, equatorial axis 16.5-29.6μm long, 3-colporate, colpus generally narrow, ora lalongate, with two ends connected with the thinned part of exine, forming a H-shape.  There are 4 thickenings where colpi and ora pass across, or sometimes the thickenings indistinct, forming a ring.  Stratification couspicuous or inconspicuous. Ornamentation of exine obscure, rarely obscurely reticulate under light microscope, but

conspicuously fine-reticulate, finely reticulate-foveolate, foveolate, striate-reticulate and shortly striate under scanning electron microscope.

     A key to the genera based on pollen grains is provided and the general morphology

of 6 genera: Paliurus, Ziziphus, Chaydaia, Berchemia, Berchemiella and Rhamnella are

described.

     Based on 4 thickenings and H-shape, pollen grains of the tribe Zizipheae may be divided into two groups: 1. the four thickenings rather larger and conspicuous, or stretched along the colpus in some species, H-shape distinct, e.g. in Berchemiella, Chaydaia and Rhamnella, and 2. the four thickenings smaller, sometimes forming a ring, H-shape more or less conspicuous, e.g. in Berchemia, Paliurus and Ziziphus.

     With respect to the concept of the genera Berchemiella and Berchemia, there were two different ideas among a number of taxonomists. H. Koidzumi, J. Ohwi and S. Kitamura place the former in Berchemia as a section, but on the contrary, T. Nakai, T. Yamazaki and K. Suessenguth consider Berchemiella and  Berchemia as two separate genera.  The data from pollen morphology support the latter treatment.

     Berchemia is closely related to Berchemiella, Chaydaia and Rhamnella in the habit

and the floral morphology, but differs from the others by its disc well-developed, eularged and becoming cup-shaped in fruit. They are also different from each other in the characters of pollen grains.

      T. Yamazaki places the genus Chaydaia in Rhamnella as a section, but according to the pollen morphology to treat Chaydaia and Rhamnella as two independent genera woild be reasonable.

1.  Murraya, together with the closely allied genera Clausena and Glycosmis

makes up the subtribe Clauseninae of the tribe Clauseneae in the rutaceous subfamily

Aurantioideae.  The center of distribution of the genus Murraya lies in southern China

and Indo-Malaysia, with a few small endemic species or varieties stretching to Sri Lanka and to New Caledonia and northeastern Australia.  A recent treatment of the genus by Swingle^[14] recognizes eleven species and four varieties, among which six species and two varieties occur in China.  Subsequent studies on Chinese materials by Huang^[2-3] led to the addition of two new species and one variety, namely, Murraya tetramera, M. Kwangsiensis, and M. kwangsiensis var. macrophylla; the former species, M. tetramera, has since been found to be identical with M. euchrestifolia^[4-5]. Huang also reinstated M. exotica as a species distinct from M. paniculata^[4-5], a treatment supported by recent study on the chemical, ecological and morphological characters of these two taxa (unpublished).

Moreover, two of the varieties recognised by Swingle, namely, M. paniculata var. omphalocarpa and M. alata var. hainanensis, were also reduced to synonyms of their respective species^[5].  Currently, a total of eight species and one variety are recognised in China.

     Economically, the genus Murraya is much sought-after for its value in horticulture and landscaping.  The fresh leaf of M. koenigii is a constant and essential component in preparing curry.  Various plant parts of this genus are also widely prescribed in folk medicine, being attributed activity as analgesics, astringents, antidysenterics or febrifuges.  The root and stem of M. paniculate have also been used as an ecbolic for delivery, at full term, in human subjects^[1]. Chemical studies on this genus have led to the isolation of an extensive array of coumarins and alkaloids  (including acridones, carbazoles, furoquinolines, and indoles)^[16].  Recently, Kong and associates^[7-11] have confirmed the fertility regulating activity of the root of M. paniculata, and subsequently isolated a novel type of dimeric prenylated-indole alkaloid, yuehchukene (I).  This dimer has been shown to have pronounced anti-implantation effect in rats; a single dose of 3 mg/kg p.o. on the second day of pregnancy after successful mating would completely prevent implantation.  However, the yield of yuehchukene obtained from M. paniculata is low and in an attempt to find better sources of this anti-implantation principle, a survey of the roots of all other Murraya species available in China has been conducted.  Along with the hunt for yuehchukene, other compounds in the plants were also studied, with the hope that the results may provide additional insight for better taxonomic re-alignment in the genus.

     2.  Yuebchukene was found in the root samples of three species, namely, M. alata,

M. exotica and M. paniculata (in cluding two samples of M. paniculata var. omphalocar-

pa from Taiwan).  From the same sources of materials, a number of 8-prenylated cou-

marius, but no carbazole, were also isolated. Four of the remaining species, viz. M. cre-

nulata, M. cuchrestifolia, M. koenigii and M. microphylla, were found to contain the car-

bazole girinimbine; murrayafoline-A was also isolated from M. crenulata and M. euchre-

stifolia. The last species, M. kwangsiensis, was found to contain an unidentified carba-

zole.  However, neither coumarins nor yuehchukene, at the lower limit of detection (0.1

mg/100 g), were found in these five species. The distribution of these major groups of

chemical constituents is summarised in Table 1.

     3.  The two groups of species also differ from each other by a combination of se-

veral morphological characters.  Plants of the first group, which contain yuehchukene

and 8-prenylated coumarins but no carbazole, have straw to light greyish yellow stems

and root bark, larger petals (1-2cm long), and red, ellipsoid fruits.  On the other

hand, plants of the second group, characterized by the presence of carbazoles and the

absence of yuehchukene and 8-prenylated coumarin, have dark brown stems and root

bark, smaller petals (4-7 mm long), and purplish black and globular to ellipsoid fru-

its.

      4.  In a recent treatment of the genus, Swingle^[14] indicates that the species he re-

cognised fall into 2 or 3 groups, not as yet adequately studied.  However, he did not ex-

pand further on this obervation and shed light on where to delimit the groups he allu-

ded to.  Our results demonstrate that the eight species of Murraya in China can be di-

vided into two groups, which differ from each other in both external morphology and

chemical constituents.  Accordingly, to reflect the relationship among the eight species

found in China, we find it appropriate to divide the genus into two sections. This idea

was also conceived by Tanaka^[15], based solely on morphology of the plants, and presen-

ted in an older monograph of the genus (under the generic name Chalcas) published in

an obscure journal issued in Taiwan during Japanese occupation. Tanaka's paper was

made available to us after we had completed our analysis and drawn up our taxonomic

interpretation.  Tanaka's classification basically matches the sections we intended to

propose.

This paper deals with the taxonomy and geographic distribution of the ge-

nus Chrysosplenium L. in China.

     Based on the characters and evolution of the seed, capsule, disk, ovary and leaf, the

species of this genus can be grouped into 2 subgenera, 5 sections and 16 series.  There

are 2 subgenera, 5 sections and 11 series in China.  They are as follows:

     I.  Subgen. Gamosplenium Maxim. emend. J. T. Pan

     Leaves alternate.

     Lectotype: Chrysosplenium carnosum Hook. f. et Thoms.

     1.  Sect. Alternifolia Franch. emend. J. T. Pan

     Seeds smooth and glabrous.

     Type: Chrysosplenium alternifolium L.

      (1)  Ser. Nudicaulia Maxim. emend. J. T. Pan

     Disk obscure or absent; ovary nearly half-inferior, sometimes mostly inferior; cap-

sule generally subtruncate and emarginate at top and bilobed with equal and horizontal-

ly divaricate or suberect lobes; seeds smooth and glabrous.

     Type: Chrysosplenium nudicaule Maxim.

      (2)  Ser. Alternifolia Maxim. emend. J. T. Pan

     Disk 8-lobed; ovary nearly half-inferior; capsule generally subtruncate and emar-

ginate at top, and bilobed with equal and horizontally  divaricate lobes;  seeds smooth

and glabrous.

      Type: Chrysosplenium alternifolia L.

     2.  Sect. Nephrophylloides Turcz.

     Seeds minutely papillose or pilose.

     Type: Chrysosplenium sedakowii Turcz.

      (1)  Ser. Macrophylla Franch. emend. J. T. Pan

     Disk obscure or absent; ovary nearly half-inferior; capsule nearly truncate and em-

arginate at top, and bilobed with equal lobes; seeds minutely papillose.

     Type: Chrysosplenium macrophyllum Oliv.

      (2)  Ser. Ovalifolia Maxim. emend. J. T. Pan

     Disk generally 8-, rarely 4-, lobed, papillae absent around disk; ovary mostly infe-

rior; capsule subtruncate and emarginate at top; seeds minutely papillose or pilose.

     Type: Chrysosplenium ovalifolium M. Bieb. ex Bunge

      (3)  Ser. Lanuginosa Hara, emend. J. T. Pan

     Papillae numerous, brown around reduced disk; ovary mostly inferior; capsule ne-

arly truncate and emarginate at top; seeds minutely papillose.

     Type: Chrysosplenium lanuginosum Hook. f. et Thoms.

 

     II.  Subgen. Chrysosplenium

     Leaves opposite.

     Type: Chrysosplenium oppositifolium L.

     1.  Sect. Trichosperma J. T. Pan, sect. nov.

     Capsule not truncate at top, and bilobed with subequal, suberect or divergent lobes.

     Type: Chrysosplenium trichospermum Edgew. ex Hook. f. et Thoms.

     This section is divided into 4 series in the world, with only 1 in China.

     (1)  Ser. Nepalensia Maxim. emend. J. T. Pan

     Disk obscure or absent; ovary generally mostly inferior;  cassule not truncate at

top, and bilobed with subequal and suberect or divergent lobes; seeds smooth and gla-

brous.

      Type: Chrysosplenium nepalense D. Don

     2.  Sect. Grayana J. T. Pan, sect. nov.

     Capsule bilobed with distinctly unequal and ascending lobes.

     Type: Chrysosplenium grayanum Maxim.

     This section consists of 4 series in the world, with 3 series in China.

      (1)  Ser. Sinica Maxim. emend. J. T. Pan

     Disk obscure or absent; ovary nearly half-superior; capsule bilobed with distinctly

unequal and ascending lobes; seeds minutely papillose.

      Type: Chrysosplenium sinicum Maxim.

      (2)  Ser. Esulcata Franch. emend. J. T. Pan

     Disk (4)-8-lobed; ovary generally half-inferior; capsule bilobed with unequal and

ascending lobes; seeds minutely papillose or pilose.

     Lectotype: Chrysosplenium dubium J. Gayex DC.

      (3)  Ser. pilosa maxim. emend. J. T. Pan

     Disk obscure or absent; ovary nearly half-inferior; capsule bilobed with distinctly

unequal and ascending lobes; seeds distinctly longitudinally ll-18-costate and minu-

tely papillose or tuberculate on the ridge.

      Type: Chrysosplenium pilosum Maxim.

      3.  Sect. Chrysosplenium

      Capsule nearly truncate and emarginate at top, and bilobed with equal and horizon-

tally divaricate lobes.

      Type: Chrysosplenium oppositifolium L.

      (1)  Ser. Romosa J. T. Pan, ser. nov.

      Disk distinctly 8-lobed, papillae sparse, brown around disk; ovary mostly inferior; ca-

psule nearly truncate and emarginate at top, and bilobed with equal and horizontally

divaricate lobes; seeds smooth and glabrous.

      Type: Chrysosplenium ramosum Maxim.

      This series is monospecific one, also occurring in China, namely C. ramosum Maxim.

      (2)  Ser. Delavayi Hara

      Disk distinctly 8-lobed, Papillae sparse, brown around the disk; ovary mostly infe-

rior; capsule nearly truncate and emarginate at top, and bilobed with equal and hori-

zontally divaricate lobes; seeds distinctly longitudinally 10-16-costate and transverse-

ly striate on the ridge.

      Type: Chrysosplenium delavayi Franch.

 

      This series can be considered as the most advanced one in the Chrysaspleninm L.

      So far, the Chrysosplenium L. comprises 64 species in the world, among which 1 spe-

cies is found in North Africa, 2 in South America, 4 in Europe, 5 in North America, 56

in Asia, of which 3 occur in Sikkim, 5 Bhutan, 5 Mongolia, 6 north Burma, 6 Korea, 7

north India, 8 Nepal, 12 Japan, 17 U.S.S.R. (of which 3 also in Europe), 34 China (in-

cluding 22 endemic species and 3 new species).

      In China, Fujian and Guangdong Provinces and Zhuang Autonomous Region of Gu-

angxi each has only 1 species, Taiwan, Zhejiang, Shanxi and Hebei Provinces and Uy-

gur Autonomous Region of Xinjiang each has 2, Anhui, Jiangxi and Hunan Provinces

each has 3, Qinghai Province 4, Heilongjiang, Liaoning and Guizhou Provinces each has

5, Jilin and Hubei Provinces each has 6, Gausu Province 8, Shaanxi Province and Xi-

zang (Tibet) Autonomous Region each has 10, Yunnan Province has 11, Sichuan Provi-

nce has 14.

     Thus the distribution centre of this genus should be in the north temperate zone

of Asia, and the region covering Shaanxi Gansu, Sichuan, Yunnan and Xizang may be

regarded as an important part of this centre.

     The 7 species of Ser.  Nudicaula Maxim. emend. J. T. Pan can be considered as the

most primitive ones in this genus. They are mostly distributed in Shaanxi (Qin Ling),

south Gansu, southeast Qinghai, southwest Sichuan and nothwest Yunnan of China. This

region may be considered as the centre of the origin (or at least differentiation) of this

genus.

     The new species and the new varieties described in this paper are as follows: C. hy-

drocotylifolium Levl. et Vant. var. emeiense J. T. Pan, C. taibaishanense J. T. Pan, C.

lixianense Jien ex J. T. Pan, C. qinlingense Jien ex J. T. Pan.

A revision of the Chinese species of Androsace updates our knowledge of

the genus by providing a brief historical survey, character analysis, discussion on gene-

ric relationships and geographical distribution, and a key to species currently recogni-

zed. For the sake of completeness, the key is supplemented by an enumeration, and a

record of the known distribution of each species.  Furthermore, some specimen citations

and additional notes on species previously very incompletly known are also included.

Seven new species and two infraspecific taxa are described.