作 者 ：Hong De-Yuan
期 刊 ：植物分类学报 1984年 3期
Keywords:Campanulaceae,
Abstract:
Echicocodon Hong (Wahlenbergieae); Gen. nov.
Calyx 2-5-saepe 4-fidus; lobis utrinque 2-4-lobulis spiniformibus praeditis. Corolla tu-
bulosa; ad medium parterm (3-) 4 (-5)-lobata. Stamina (3-) 4 (-5); libera; sed inter
se eonniventia; filamentis basi parum expansis. Ovarium fere inferum; 3-5-1oculare; stig-
mata 3-5; demum recurva; linearia; ovula ∞. Capsula globosa; 3-5-locularis; spice locu-
licide dehiscens; valvis calycis lobis alternantibus. Semina ∞ ; minima; ellipsoidea; obtuse tri-
quetra.——Herbae perennes; lactesentes; radicibus palaribus crassiusculis. Folia alterna; pin-
natipartita. Flores solitarii terminalesque vel 2-3 in cymam conferti.
Genus monotypicum; in provincia Hubei Sinae cresens.
Typus generis: Echinocodon lobophyllus Hong.
Echinocodon lobophyllus Hong; sp. nov. plate 1
Herbae diffusae; omnino glabrae; radicibus palaribus ad 5 mm crassis. Caulis ad 40 cm
longus; ramosissimus. Folia alterna; petiolis 5-10 mm longis; laminis ellipticis; 5-20 mm
longis; 3-15 mm latis; basi anguste cuneatis; apice obtusis; pinnatisectis vel ad medium
pinnatipartitis.
Flores solitarii terminales vel 2-3 in cymam conferti; pedicellis 1-5 cm longis. Caly-
cis lobi ovato-lanceolati; 2-6 mm longi; lobulis spiniformibus exclusis 1-3 mm lati. Corol-
la purpureo-caerulea; tubulosa; 3-4.5 mm longa; ad medium (3-)4(-5)-lobata; lobis la-
te ovato-diltoideis; ad 3 mm latis. Stamina inter se conniventia; filamentis liberis; 1.5 mm
longis; basi expansis; ciliatis; antheris oblongis; 1 mm longis. Stylus 1 mm longus; stigmata
linearia; demum recurva. Capsula globosa; 3-5 mm diam.; sed parte supera conica et 2 mm
longa. Semina minima; luteo-fusca; ellipsoidea; obtuse triquetra; 0.3 mm longa.
China: Hubei Province; Yunxi County; near the town; 300 m alt.; 1 Jul. 1983. Ma Yu-
an-jun and Hong De-yuan PB83006 (holotype; PE); the same locality; 11 Jul. 1978; Ma
Yuan-jun 3921.
The new genus; Echinocodon Hong; shows its systematic position in the tribe Wahlen-
bergieae by the inferior ovary and capsule which loculicidally dehisces above the calyx and
is closely related to the genera Codonopsis; Platycodon and Wahlenbergia; from all of which
it differs in having the calyx lobes with spinelike lobules and the pinnatisect or pinnatipar-
tite leaves. From Codonopsis it differs also in having the linear stigma lobes; from Platyco-
don also in the capsule valves alternate with the calyx lobes and from Wahlenhergia also in
having the 4(5)-colpate pollen grains.
Meiosis in pollen mother cells was examined and; 8 bivalents in MI and 8 chromoso-
mes in MII were always observed (Plate 2: 1-2). The chromosomt number is thus de-
termined to be n=8.
The pollen grains taken from the flowers which were fixed in the fields with Carnoy
II fixative (6:3:1 absolute alcohol/chloroform/glacial acetic acid) were examined without
further treatment under SEM; and under LM after acetolysis. The result shows that they
are oblate; 4(5)-colpate (Plate 2: 3-4); with colpi 10.5μm long and 2.5μm wide and
with a smooth colpus membrane (Plate 2: 5). The exine is 2-layered; with a distinct bacu-
late layer (Plate 2:7-8). The sexine surface is covered with spinules almost regularly spa-
ced; 0.6μm high and basally divided. The sexine between spinules consists of short ridges
(Plate 2: 6).
The new genus is closely related to the genera Codonopsis; Wahlenbergia and Platyco-
don from gross morphological point of view; but its pollen grains differ markedly from
all of them. The pollen grains in Codonopsis are longly 5-colpate; and with the sexine consis-
ting of a low relief reticulum; those in Platycodon longly 5-colporate and those in Wahlen-
bergia 3-porate. The pollen type of the new genus Echinocodon with short colpi is therefore
probably derived from the longly colpate type of pollen like that of Codonopsis or directly
from longly colporate type like that of Platycodon; and is likely more primitive than that
in Wahlenbergia.