CHROMOSOME NUMBERS IN THE GENUS ANTHURIUM (ARACEAE) II

Chromosome numbers were determined for 86 Anthurium species. Fifty-one of these were newly determined with counts ranging from 2n = 24 to 66 and 30 being the most common. All known Anthurium chromosome numbers were summarized, and 43 taxonomic changes were made in the previous reports to reflect current taxonomy. In terms of somatic chromosome numbers, the numbers form four polyploid series of 20–40–60, 24–30–48–84, 28–56 and 30–60–90–ca. 124. Paleoaneuploidy, polyploidy and B-chromosomes are basic features of the genus, but subsequent recent aneuploidy is not. The exact nature of chromosome evolution in Anthurium remains to be elucidated.     

关于岩芋属二个种的模式化问题

岩芋属Remusatia(Araceae)是一个特征鲜明的属,共含三种,即R. vivipara(Lodd. )Schott,R. hookeriana Schott,R. ornata(Schott)H. Li et Q.F.Guo。Gonatanthus (?) ornatus Schott中的 (?) 这类植物转入Remusatia属,其名应为秀丽岩芋Remusatia ornata(Schott)H. Liet Q. F. Guo. Gonatanthuc ornatus 的模式标本是Hooker f.s.n.采自印度喀西山,现只有Schott绘制的模式图照片;Schlagintweit n.313,亦采自喀西山,是Krause(1920)补充描述本种的重要凭证标本,现只有遗图。R. hookeriana Schott(1857)的模式标本Hooker f.s.n.产锡金,Krause(1920)发表的图和描述的大部分可作为该种的凭证,是一个不同于R. ornata的好种。Rao et Verma(1968)所描述的Gonatanthus ornatus应是Remusatia hookeriana。     

天南星科岩芋属的细胞地理学研究

本文报道了岩芋属三个种的染色体数目和核型:岩芋Remusatia vivipara是三倍体,核型公式为K(2n)=3X=42=42m;早花岩芋R. hookeriana为二倍体,核型公式为K(2n)=2X=28=22m(6SAT) 6m(2SAT);秀丽岩芋R. ornala,也是三倍体,核型公式为K(2n)=3X=42=36m(3SAT) 3sm 3st。在岩芋属中,岩芋是一个比较原始的种,秀丽岩芋较进化。岩芋属是热带非洲和热带亚洲间断分布的小属,它的原始类群岩芋(R. vivipara)的原始居群(二倍体居群)分布在印度南部,因而作者没想,古南大陆是岩芋属的起源地,本属向热带亚洲的扩散是与第三纪时喜马拉雅造山运动相联系的。     

CHROMOSOME NUMBERS IN THE GENUS ANTHURIUM

Chromosome numbers were determined for 63 Anthurium species. Thirty-eight of these were newly determined. Generally the present work confirmed existing chromosome counts when these were available for comparison. The most common somatic chromosome number found was 30, but counts ranged from 2n = 20 to 90. In a few instances conflicting counts were obtained. B chromosomes were found frequently in Sect. Cardiolonchium and varied in number from one to three. Four polyploid series were evident from all available counts: 20-40, 24-30-48-84, 28-56 and 30-60-90-ca 124. Most species were part of the polyploid complex based on 30. Although species were not observed with n = 5, 6 or 7, movement among the basic numbers was considered to have occurred at this level. The relationship among these basic numbers and n = 15 (x₂) is still obscure.     

CYTOLOGICAL ANALYSIS OF ANTHURIUM ANDRAEANUM (ARACEAE), ITS RELATED TAXA AND THEIR HYBRIDS

Karyotypes and meiotic configurations of Anthurium andraeanum and closely related taxa were analyzed. The karyotypes of A. andraeanum, A. caperatum, A. formosum, A. kamemotoanum, A. lindenianum, A. roseospadix, A. cf. sanctifidense, A. subsignatum, A. garagaranum, and an unidentified Anthurium sp. commonly consisted of four large metacentric or submetacentric chromosomes, two fairly large acrocentric chromosomes, two satellite chromosomes, and 22 smaller chromosomes. Variation in the karyotypes of A. nymphaeifolium and A. ochranthum suggested chromosomal rearrangement in the genus. All taxa showed 15 pairs of chromosomes at prometaphase I of meiosis in pollen mother cells. Four large chromosomes appeared as ring bivalents, and the rest of the chromosomes appeared as either ring or rod bivalents. Regular bivalent formation at prometaphase I of meiosis in pollen mother cells of species hybrids suggested close genomic relationships among parental taxa. On the other hand, reduction of pollen fertility estimated by pollen stainability in those hybrids suggested genetic divergence of species.     

THE OCCURRENCE OF TRICHOSCLEREIDS IN THE MONSTEROIDEAE (ARACEAE)

Nicolson, Dan H. (Cornell U., Ithaca, N. Y.) The occurrence of trichosclereids in the Monsteroideae (Araceae). Amer. Jour. Bot. 47(7): 598–602. Illus. 1960.—A study was made on the presence, distribution, and frequency of trichosclereids within the leaf-blade, petiole, and stem of 32 species of Monsteroideae and I species of Pothoideae. Trichosclereids occurred in all species studied. Distribution and frequencies of trichosclereids were variable. Trichosclereids occurred more consistently in the petiole than in the leaf-blade or stem tissues. A new report of trichosclereids outside of the Monsteroideae, in Pothos repens (Lour.) Druce of the Pothoideae, is made. The tribe Spathiphylleae (Spathiphyllum and Holochlamys) was found to be characterized in part by large numbers of trichosclereids occurring in groups within the leaf-blade.     

THE POLLINATION BIOLOGY OF TUCKAHOE,PELTANDRA VIRGINICA (ARACEAE)

This study describes the specialized brood-site-based pollination system of Peltandra virginica Kunth (Araceae) with the chloropid fly Elachiptera formosa Loew and provides experimental evidence that gender-related changes in floral odor composition synchronize pollinator behavior with the blooming sequence. P. virginica is protogynous and does not self-pollinate because of a strong temporal separation in sexual function, and it is dependent upon insects for pollination because the spathe completely surrounds the spadix during the pistillate stage. Field observations conducted in central New Jersey and southeastern Pennsylvania showed that E. formosa is closely associated with P. virginica inflorescences. Within the floral chamber, E. formosa adults feed on pollen, mate, and find oviposition sites while the larvae complete their development. Although drosophilid and syrphid flies were collected and reared from inflorescences of both sexual stages, only E. formosa emerged from pistillate-stage inflorescences and adult E. formosa rapidly transferred fluorescent dye particles between inflorescences of both sexual stages in laboratory enclosures. These findings indicate that this fly species is the primary pollinator at our study locations. Field censuses demonstrated that although E. formosa visited P. virginica inflorescences of both sexual stages with equal frequency, the female flies preferentially oviposited within pistillate-stage inflorescences. Analysis of floral volatiles with gas chromatography-mass spectrometry showed that only the spathes emit the floral fragrance and that the composition of the floral volatiles changed during the transition from pistillate to staminate stage. A particularly noticeable change occurred in the emission ratio of the two primary floral odor components, 4,5,7-trimethyl-6,8-dioxabicyclo[3.2.1.]octane and an unidentified chemical analog with molecular weight of 142. The relationship between floral volatile composition and fly oviposition behavior was evaluated using sham inflorescences placed in the P. virginica study population. The sham inflorescences were constructed by covering spadices dissected from mature inflorescence buds with spathes excised from different-age inflorescences. After a 2-hr-long exposure period, sham inflorescences fitted with pistillate-stage spathes contained more E. formosa eggs than the sham inflorescences with staminate-stage spathes. However, the highest number of ovipositions occurred in sham inflorescences fitted with spathes excised from mature inflorescence buds. The fragrance emitted by these spathes was composed almost entirely of the two principal odor components. The decline in ovipositions observed in both real and sham inflorescences corresponded to an increase in the emission ratio of 4,5,7-trimethyl-6,8-dioxabicyclo[3.2.1.]octane to the molecular weight 142 analog. This suggests that gravid flies searching for oviposition sites used the ratio of the two primary floral volatile components as an inflorescence gender or age recognition cue.     

BEETLE POLLINATION OF DIEFFENBACHIA LONGISPATHA (ARACEAE)

Dieffenbachia is an monoecious understory herb of tropical rain forests that exhibits a complex and specialized relationship with its beetle pollinators. The erect protogynous inflorescence has the spadix divided, with the female flowers in the basal half and male flowers in the upper half. Dieffenbachia longispatha Engler & Krause is pollinated by scarab beetles in the genera Cyclocephala and Erioscelis. The enveloping spathe of the inflorescence opens in the evening, but no flowers are sexually functional until the stigmas become receptive about 24 hr later. Beetles fly to the inflorescence in darkness, suggesting that floral odors play a role as an attractant. Beetles remain in the inflorescence for 24 hr, eating protein-rich staminodia that surround the stigmas. On the evening of the third day the anthers dehisce and beetles become covered with pollen as they crawl up the spadix in the process of leaving. Beetles fly an average of 80 m between inflorescences, usually to the nearest female inflorescence, although distances of 400–1,000 m have been observed. Minimal estimate of genetic neighborhood sizes are large for D. longispatha (750 to 8,900 plants) and neighborhood areas encompass 41,000 to 67,000 m². Experiments demonstrate that the species is self-compatible and that fruit production is pollinator limited.     

天南星科的生态地理和起源

本文将天南星科105个属的分布区归纳为12个分布类型和29个亚型,对每一类型的属进行生态地理分析。本科计有88个热带属,占全科的83.8％,是一个热带科。全科有两大分化中心:热带亚洲为属的多样化中心,热带美洲是种的分化中心。根据天南星科各属的生态地理研究,结合到科的系统发育程序,作者得出结论说:天南星科的原始类群在晚白垩纪时起源于亚洲大陆南缘,即欧亚古陆的亚洲南缘地带的水域生态环境。     

赤■属的胚胎学研究(英)

描述了葫芦科赤爬属植物生活史的主要过程以及胚胎学的重要特征,它们是：腺质绒毡层,胞质分裂同时型,小孢子四分体四面体型和等面体型,花粉粒散发时具两细胞,双珠被,厚珠心,寥型胚囊,珠孔端受精,胚胎发育柳叶菜型。     

HEAT-PRODUCTION AND CROSS-POLLINATION OF THE ASIAN SKUNK CABBAGE SYMPLOCARPUS RENIFOLIUS (ARACEAE)

The Asian skunk cabbage Symplocarpus renifolius has an exothermic spadix on which about 100 flowers bloom in very early spring when effective pollinators such as bees and drone flies are inactive. This species is protogynous; female phase and male phase took 6.8 ± SD 5.8 days and 16.7 ± 5.7 days, respectively, with a short transitional phase of bisexuality (2.1 ± 0.9 days). The spadices produced heat 24 hours/day throughout female and bisexual phases, but temperature dropped quickly after the beginning of male phase. Although self-compatibility was expected from the flower structure, the basipetal flowering, and the absence of effective pollinators, bagging tests demonstrated that they rarely produce seeds without crossing. The spadices were visited by small numbers of invertebrates throughout the flowering season. Of these invertebrates, house flies, rove beetles, and mosquitos were the likeliest pollinators, since they are probably attracted both to the pollen produced in male phase and to the stench or carbon dioxide in female phase. On two female spadices with immature male flowers, we fortuitously collected a rove beetle and a mosquito that carried some pollen grains; these had to have been transported from other S. renifolius spadices. This infrequent and ineffective pollination appears to explain why as low as 13% of spadices set seeds in a natural population. We examine alternative hypotheses to explain production of heat in spadices of skunk cabbage.     

赤瓟属的胚胎学研究(英)

首次描述了葫芦科赤Ｂｏ属植物生活史的主要过程以及胚胎学的重要特征,它们是：腺质绒毡层,胸质分裂同时型,小孢子四分体四面体型和等面体型,花粉粒散发时具两细胞,双株被、厚株心,蓼型胚囊同时,珠孔端受精,胚胎发育柳叶菜型。     

SURVEY OF SHOOT ORGANIZATION IN THE ARACEAE

Shoot organization is examined in 87 species from 29 genera representing all six subfamilies of the Araceae and of Acorus, which has been placed in a separate family. Within each taxonomic group examined, the details of shoot organization are presented, including the types of segments and articles which make up the shoot, the degree of expansion of leaf blades, and the placement of buds along the shoots. Literature on shoot organization of the 29 genera is reviewed. The degree of correlation between shoot organization characteristics and systematic groupings is examined, and the utility of these characteristics for systematics is evaluated. It is found that within the taxa observed, the pattern of shoot organization provides a distinctive “fingerprint” at the generic or sectional level, sufficient for determination of the group. Some patterns which appear are pointed out: taxa with bisexual flowers usually produce a single inflorescence at the terminus of a vegetative article. A few taxa with bisexual flowers produce pairs of inflorescences at the ends of articles. Multiple inflorescences (more than two) at an article terminus occur only among taxa with unisexual flowers. Multiple inflorescences are associated with anisophyllous or homeophyllous sympodial growth, while single or paired inflorescences are associated with homeophyllous or intermittent homeophyllous sympodial growth. These patterns might be understood as the result of selection for flexibility of reproductive effort and of seasonal reproduction.     

金盏苣苔属(苦苣苔科)的第二次校订

金盏苣苔属(Isometrum Craib)属于苦苣苔亚科(Cyrtandroideae)长蒴苣苔族(Didymocarpcae),是由W.G.Craib 1919根据I.farreri Craib建立的,同年他又把Didissandra glandulosa Batalin置于该属,1960年B.L.Burtt又把Didi-sandra Clarke中的4个种(即:D.prumuliflora Batalim,D.giraldii Diels,D.fargesii Franch.和D.leucantha Diels)移入该属。作者在编写中国植物志苦苣苔     

IRREGULAR FLORAL DEVELOPMENT IN CALLA PALUSTRIS (ARACEAE) AND THE CONCEPT OF HOMEOSIS

About two-thirds of the more than 100 genera in the Araceae lack tepals and their absence is considered derived. Unlike most of these atepalate genera, Calla palustris has about twice as many stamens per flower. Using epi-illumination microscopy, we studied floral development in Calla to see if the supernumerary stamens form in positions corresponding to tepal positions in perigonate Araceae. If so, this would be an example of homeosis—in this case, the replacement of tepals with stamens—in the evolution of this genus. We found the positions of stamen primordia in many floral buds too irregular to conclude that they replace tepals positionally. However, in more regular floral buds the first formed stamens do form in what correspond to tepal sites in related genera. If the immediate ancestor to Calla had tepals, as is generally assumed, stamen positions in the more regular flowers, at least, support a homeotic interpretation. There is no evidence that the supernumerary stamens arise by dédoublement, but since morphogenesis in Calla is only partly comparable to other aroids, and the phylogeny in the family is not well understood, further studies are needed to resolve the interpretation of the flower in Calla. With regard to systematics and evolution, the absence of tepals in Calla may not be homologous with atepaly in other members of the family, as has been assumed for the past century.