Genera Of Lauraceae Research Articles

High-Resolution Tandem Mass Spectrometry for Metabolic Profiling of Ocotea diospyrifolia (Meisn.) Mez Leaves.

Ocotea is an important genusof Lauraceae plant familythat comprises over 400 species, many of which pose challenges in taxonomicdifferentiation due to their complex botanical characteristics. Chemosystematics, and more recently, chemophenetics, have emerged as valuable tools to address these challenges based on their natural products (NPs) composition. O. diospyrifolia (Meisn.) Mez is a poorly studied species with known pharmacological potential. Here, we applied ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC-HRMS) allied to a curated in-house database with all previous isolated NPs from the Ocotea genus (OcoteaDB), gas phase fragmentations reactions, and biosynthesis. The strategy resulted in compounds annotated in confidence levels 2 (n=27), 3 (n=231), and 4 (n=21) according to the Metabolomics Standards Initiative (MSI). Additional annotations based on fragmentation proposals (n=16) were also included. The study revealed that O. diospyrifolia is a great alkaloid producer, even though different lignoids, which also comes from the shikimate pathway, were annotated. Additionally, the flavonoid profile predominantly consists of flavonol glycosides, complementing prior reports. This study provides the first comprehensive chemical profile of O. diospyrifolia leaves, which corroborates the chemotaxonomy of the species, and also contributes to further characterization studies, as the UHPLC-HRMS data is publicly available.

Comparative Analysis of Chloroplast Genomes of "Tiantai Wu-Yao" (Lindera aggregata) and Taxa of the Same Genus and Different Genera.

Lindera aggregata is a species of the Lauraceae family, which has important medicinal, economic and ornamental values. In this study, we sequenced, assembled and annotated the chloroplast genome of L. aggregata and reannotated and corrected eight unverified annotations in the same genus. The chloroplast genomes taxa from Lindera and from different genera of Lauraceae were compared and analyzed, and their phylogenetic relationship and divergence time were speculated. All the 36 chloroplast genomes had typical quadripartite structures that ranged from 150,749 to 154,736 bp in total length. These genomes encoded 111-112 unique genes, including 78-79 protein-coding genes, 29-30 tRNA and 4 rRNA. Furthermore, there were 78-97 SSRs loci in these genomes, in which mononucleotide repeats were the most abundant; there were 24-49 interspersed repeats, and forward repeat types were the most frequent. The codon bias patterns of all species tended to use codons ending with A or U. Five and six highly variable regions were identified within genus and between genera, respectively, and three common regions (ycf1, ndhF-rpl32 and rpl32-trnL) were identified, which can be used as important DNA markers for phylogeny and species identification. According to the evaluation of the Ka/Ks ratio, most of the genes were under purifying selection, and only 10 genes were under positive selection. Finally, through the construction of the evolutionary tree of 39 chloroplast genomes, the phylogenetic relationship of Lauraceae was clarified and the evolutionary relationship of Lindera was revealed. The species of genus Lindera experienced rapid adaptive radiation from Miocene to Pleistocene. The results provided valuable insights for the study of chloroplast genomes in the Lauraceae family, especially in the genus Lindera.

Cassytha (Lauraceae) in Africa and the description of a new species from Gabon

Cassytha is a (hemi)parasitic genus of Lauraceae with its main diversity in Australia. To characterise a new species from Gabon, we studied and revised the African species of this genus. Previously 3 or 4 taxa were recognised to occur in Africa, in this study we recognise 5 species; next to our new species we resurrect Cassytha schliebenii to species level. The new species, Cassytha graminicola, is parasitising on monocotyledons, especially grasses, and is likely the first recorded annual among the Lauraceae. Cassytha paradoxae from the New World also seems to use monocotyledons as host, and should be recognised as a valid species.

The first paleoxylotomical evidence from the Mid-Eocene Climate Optimum from Turkey

Petrified wood is important evidence of forest type and past climate. Studies from mainly the Neogene of Turkey described many fossil woods, and revealed valuable information about the paleoenvironment structure and climate. This is the first occurrence of plant macrofossils belonging to the Middle Miocene Climate Optimum, a crucial period in Earth's history, found in Turkey. The purpose of the present study is to investigate, for the first time, the Middle Eocene Climate Optimum of Turkey through the first identification of two paleoxylotomical findings of Lutetian age from Central-North Turkey. After working on the thin wood sections, a new fossil genus of Lauraceae, Actinodaphnoxylon gen. nov. was described with a type species of Actinodaphnoxylon zileensis sp. nov. Another coniferous specimen was described as Pinuxylon cf. P. tarnocziense. These species indicate the presence of warm, humid rainforest and lower mountain forest 40–41 million years ago in the middle Black Sea region (Tokat-Zile) of North-Central Turkey.

The genera of Lauraceae in Madagascar with nomenclatural novelties in Cryptocarya

Abstract Van der Werff, H. (2017). The genera of Lauraceae in Madagascar with nomenclatural novelties in Cryptocarya. Candollea 72 : 323–328. In English, English and French abstracts. Two identification keys to the genera of Lauraceae in Madagascar based on or fruiting specimens are provided. For each genus diagnostic characters, estimates of species numbers, recent literature and additional notes are included. Eight species of Ravensara Sonn. are transferred to Cryptocarya R. Br., resulting in five new combinations and three new names. A lectotype is designated for Ravensara affinis Kostermans (≡ Cryptocarya petiolata van der Werff).

Cuticular features of Cryptocarya (Lauraceae) from Peninsular Malaysia, Thailand and Indo-China and its taxonomic implications

Cuticular features potentially offer valuable information on phytotaxonomy, especially for plants that are difficult to classify or identify. Cryptocarya is one such difficult and poorly known genus, and we investigated its cuticular features to evaluate their taxonomic implications. We examined cutinized leaf epidermis and the stomatal complex for 21 species from Peninsular Malaysia, Thailand and Indo-China, as well as one species endemic to Borneo and one to Sumatra, and compared features among members of this group, between this group and congeners in the other countries, and between this group and the other genera of Lauraceae. Many of the Cryptocarya species studied have straight to slightly curved anticlinal epidermal walls and butterfly-shaped stomatal ledges, although some variation was seen in the ornamentation of the periclinal epidermal walls and the appearance of the stomatal complex. Based on these results, we recognized four groups and two subgroups among the South-east Asian species. Comparison with congeneric taxa in the other countries indicates that butterfly-shaped stomatal ledges are often shared among the species across the regions. However, no cuticular features occur exclusively in any of the species groups of Cryptocarya studied here, nor in the genus as a whole. We consider that cuticular features are useful in the recognition of infrageneric groups within Lauraceae, bearing in mind that they might have evolved in parallel in different genera.

Epitypification of the name Laurus borbonia (Lauraceae)

AbstractThe Linnaean name Laurus borbonia was lectotypified in 1966 on a 1731 Mark Catesby etching. However, as the taxonomic identity of the lectotype is ambiguous, and might relate to either Persea borbonia or P. palustris (and may even have been drawn from two different genera of Lauraceae), an epitype is designated here to maintain application of the name in its traditional sense.

Terpenoid Diversity in the Leaf Essential Oils of Himalayan Lauraceae Species

The leaf terpenoid compositions of nine Lauraceae species, viz., Neolitsea pallens, Lindera pulcherrima, Dodecadenia grandiflora, Persea duthiei, Persea odoratissima, Persea gamblei, Phoebe lanceolata, Cinnamomum tamala, and Cinnamomum camphora, collected from the Himalayan region (India) were examined by GC, GC/MS, and NMR analyses in order to determine the similarities and differences among their volatile constituents. Furano-sesquiterpenoids were the principal constituents of N. pallens, L. pulcherrima, and D. grandiflora. (E)-Nerolidol, limonene, beta-pinene, and alpha-pinene were the major constituents of P. duthiei; alpha-pinene, sabinene, and beta-caryophyllene were predominant in P. odoratissima, while the oils of P. gamblei and P. lanceolata possessed beta-caryophyllene as common major constituent. C. camphora and C. tamala were marked by the presence of camphor and cinnamaldehyde, respectively. Cluster analysis of the oil composition was carried out in order to discern the differences and similarities within nine species of six genera of Lauraceae.

Sinopora, A New Genus of Lauraceae from South China

The new genus Sinopora J. Li, N. H. Xia & H. W. Li is reported for the Lauraceae from Hong Kong in South China and is based on Syndiclis hongkongensis N. H. Xia, Y. F. Deng & K. L. Yip. The new genus is distinguished from Syndiclis Hooker f. by its trimerous flowers. The new genus is similar to Hexapora Hooker f., but its anthers are originally introrse and tubular, with two anther cells near each other and apically opening by minute pores, the staminodes as large as the stamens, but not produced above the stamens.

Are cuticular characters useful in solving generic relationships of problematic species of Lauraceae?

We report on the cuticular features of a number of Lauraceae species belonging to the genera Aspidostemon, Beilschmiedia, Cryptocarya and Potameia, all from Madagascar. The goal of this project was to ascertain if cuticular features could be used to determine the generic placement of a poorly known species previously placed in Cryptocarya and Aspidostemon and of several specimens which combine characters of Potameia and Beilschmiedia. We conclude that cuticular features define groups of species or genera of Lauraceae and that these characters are a promising tool in solving the generic placement of poorly known species or specimens which possess characters typical of more than one genus.

A Synopsis of Ocotea (Lauraceae) in Central America and Southern Mexico

Ocotea is the largest genus of Lauraceae in Mesoamerica (Central America and Southern Mexico, i.e., the area between the Isthmus of Tehuantepec in Mexico and the Panamanian-Colombian border) with 102 species recognized. The most recent treatment of Mesoamerican Ocotea was published by Carolyn Allen in 1945. It included 33 species and is now seriously outdated. A synopsis of the genus as it is currently known from Mesoamerica is presented here, consisting of a key to species, synonymy, type information, some brief notes on characters useful in their identification, and distribution by country and altitude.

A New Species of Caryodaphnopsis (Lauraceae) from Vietnam

Caryodaphnopsis bilocellata van der Werff & Dao, collected in the Cuc Phuong National Park in Vietnam and differing from the other Asian species of the genus in having 2-celled anthers, is described. Caryodaphnopsis is a small genus of Lauraceae, characterized by its opposite leaves and strongly unequal tepals, with the outer three much smaller than the inner three. A unique wood anatomical feature of Caryodaphnopsis is the presence of pyramidal, trihydrate calcium oxalate crystals in the ray cells (Richter, 1981). The genus is known from Southeast Asia (southern China, Vietnam, Laos, Cambodia, Indonesia, and the Philippines) and from the Neotropics (Brazil, Peru, Ecuador, Colombia, Panama, and Costa Rica). The Asian species have been revised by Kostermans (1974), who accepted seven species. The six neotropical species were recently described or transferred to Caryodaphnopsis (van der Werff & Richter, 1985; van der Werff, 1986, 1988, 1991; Zamora et al., 1988), but have never been revised. Most species, including all Asian species, have nine 4-celled stamens. However, the neotropical C. inaequalis (A. C. Smith) van der Werff & H. G. Richter has nine 2-celled stamens, and the neotropical C. tomentosa van der Werff has only six 2-celled stamens. Such variation in stamen configuration within the same genus is unusual among Lauraceae, but has been reported in several genera (van der Werff & Richter, 1985). We attach more importance to the opposite leaves, strongly unequal tepals, and the wood anatomy for generic delimitation and accept the variation in stamen numbers and locelli numbers in Caryodaphnopsis. During recent fieldwork in Vietnam, a species of Caryodaphnopsis was found that differed from the other Asian species in having nine 2-celled, and not 4-celled, stamens; its description follows here. Caryodaphnopsis bilocellata van der Werff & Dao, sp. nov. TYPE: Vietnam. Ninh Binh Province: Cuc Phuong National Park, H. van der Werff et al. 14250 (holotype, MO; isotypes, HN, KUN, QRS). Figure 1. A congeneris asiaticis antheris bilocellatis recedit. Trees, 25 m tall. Twigs terete, glabrous; terminal buds glabrous. Leaves opposite, chartaceous, elliptic or ovate-elliptic, 7-18 x 3-9 cm, glabrous on both surfaces, the base obtuse or acute, the apex acute, smaller leaves trinerved, larger leaves slightly triplinerved with the basal lateral veins leaving the midrib ca. 3 mm from above the base of the leaf, the lower surface glaucous, midrib and lateral veins slightly impressed on the upper surface, raised on the lower surface, tertiary venation immersed on both surfaces, petioles 10-14 mm long, glabrous. Inflorescences axillary, 5-15 cm long, glabrous, paniculate-cymosely branched. Flowers hermaphrodite, glabrous, green. Tepals 6, the outer 3 triangular, scale-like, ca. 0.4 mm long, the inner 3 broadly triangular, ca. 1.7 mm long, erect with the tip incurved, glabrous on the outer surface, sparsely pubescent on the inner surface; stamens 9, 2-celled, the outer 6 ca. 0.8 mm long, the filaments ca. 0.4 mm long, pubescent, the anthers glabrous, the locelli opening introrse; inner 3 stamens opening extrorse, 1 mm long, the filaments 0.3 mm long, pubescent, with 2 globose glands attached near the base of the anther; staminodia 3, ca. 0.5 mm long, dorsally pubescent, pressed against the ovary, with a triangular tip; ovary glabrous, 1 mm long, with a slender style; receptacle shallow, glabrous inside. Fruit unknown. Flowers April. Floral measurements were taken from alcoholpreserved material, and floral size of dried flowers will be smaller (for instance, length of inner tepals 1.2 mm). Vegetatively, Caryodaphnopsis bilocellata is quite similar to C. metallica Kostermans and C. henryi Airy Shaw and shares with those species the mostly NovoN 9: 584-586. 1999. This content downloaded from 207.46.13.114 on Thu, 26 May 2016 06:55:05 UTC All use subject to http://about.jstor.org/terms Volume 9, Number 4 1999 van der Werff & Dao Caryodaphnopsis bilocellata from Vietnam 585

Embryology and Relationships of Lauraceae (Laurales)

Embryology of Lauraceae, hitherto poorly known, was investigated on the basis of 35 species from 23 genera to contribute to a better understanding of familial and generic relationships. Data from the genera investigated and from the literature show that the genera of Lauraceae are very similar embryologically, but that differences do exist in a few characters among the genera. Based on comparisons with other families of Laurales, Lauraceae consistently had a pachychalazal ovule or seed with a ramified raphal vascular bundle at chalaza (an apomorphy) in common with Hernandiaceae. However, since several core lauralean families such as Amborellaceae, Monimiaceae, and Gomortegaceae are little known embryologically, these must be studied for critical comparison. Within Lauraceae,Cassythais clearly distinct from the rest of the family in having anab initiocellular type endosperm (a plesiomorphy, also reported inUmbellularia) instead of a nuclear type endosperm (an apomorphy) as in the rest of the family, in lacking the nucellar cap and in having the micropyle formed by both the inner and outer integument, facts supporting the traditional taxonomic placement ofCassythain its own subfamily and the remainder of the family in the other subfamily. Within the rest of the family, the amoeboid tapetum (an apomorphy) distinguishes 15 genera (Actinodaphne,Cinnamomum,Laurus, etc.) from the six genera with the glandular tapetum. In addition, a mature embryo sac protruding from the nucellus (an apomorphy) distinguishes five genera (Beilschmiedia,Caryodaphnopsis,Cryptocarya,Endiandra,Potameia) and one species ofOcotea(O. rubra) from the rest of the family. These results can properly be incorporated in a future suprageneric classification. The distinctness ofOcotearubrawithin the genus is also discussed.

Embryology and relationships of Lauraceae (Laurales)

Abstract Embryology of Lauraceae, hitherto poorly known, was investigated on the basis of 35 species from 23 genera to contribute to a better understanding of familial and generic relationships. Data from the genera investigated and from the literature show that the genera of Lauraceae are very similar embryologically, but that differences do exist in a few characters among the genera. Based on comparisons with other families of Laurales, Lauraceae consistently had a pachychalazal ovule or seed with a ramified raphal vascular bundle at chalaza (an apomorphy) in common with Hernandiaceae. However, since several core lauralean families such as Amborellaceae, Monimiaceae, and Gomortegaceae are little known embryologically, these must be studied for critical comparison. Within Lauraceae,Cassythais clearly distinct from the rest of the family in having anab initiocellular type endosperm (a plesiomorphy, also reported inUmbellularia) instead of a nuclear type endosperm (an apomorphy) as in the rest of the family, in lacking the nucellar cap and in having the micropyle formed by both the inner and outer integument, facts supporting the traditional taxonomic placement ofCassythain its own subfamily and the remainder of the family in the other subfamily. Within the rest of the family, the amoeboid tapetum (an apomorphy) distinguishes 15 genera (Actinodaphne,Cinnamomum,Laurus, etc.) from the six genera with the glandular tapetum. In addition, a mature embryo sac protruding from the nucellus (an apomorphy) distinguishes five genera (Beilschmiedia,Caryodaphnopsis,Cryptocarya,Endiandra,Potameia) and one species ofOcotea(O. rubra) from the rest of the family. These results can properly be incorporated in a future suprageneric classification. The distinctness ofOcotearubrawithin the genus is also discussed.

Sextonia, a New Genus of Lauraceae from South America

The genus Sextonia is described; it consists of two species, the rather widespread S. rubra and the new species S. pubescens, restricted to eastern Peru. Ocotea is the largest genus of neotropical Lauraceae, including at least 300 species (van der Werff, 1991). It is not surprising that with such a large number of species the genus shows considerable morphological variation, is difficult to delimit, and is in much need of a modern revision. Oftentimes the genus has been used to accommodate species that could not be adequately placed in other, better defined genera. As information from other disciplines, most notably wood and bark anatomy (Richter, 1981), has become available, some of the anomalous species have been removed from Ocotea and recognized as distinct genera. Rohwer et al. (1991) created the genus Chlorocardium for two species previously placed in Ocotea and discussed some other problematical species. I propose to recognize one of those species, until now treated as Ocotea rubra, as belonging to a distinct genus and will describe a new species of this genus as well. Sextonia van der Werff, gen. nov. TYPE: Sextonia rubra (Mez) van der Werff. Figure 1. Arbores magnae. Folia ad apices ramulorum aggregata. Inflorescentiae axillares, racemosae vel paniculatae. Tepala 6, inaequalia, 3 exteriora quam 3 interiora minora, erecta; stamina 9, 4-locellata, 6 exteriora locellis in arcu non profundo dispositis, 3 interiora locellis in 2 paribus superpositis; staminodia 3; receptaculum profundum. Fructus cupula insidens, ab ea 13 vel fere omnino obtecta. Large trees, to 45 m tall. Twigs thick, corky, terete. Leaves alternate, clustered near the tips of the branches, pinnately veined, without domatia. Inflorescences axillary, racemose or paniculate, ultimate divisions of inflorescences frequently not strictly cymose, but racemose. Tepals erect, unequal, the outer three smaller than the inner three; stamens 9, 4-celled, the outer 6 with the cells in a shallow arc, the inner 3 with the cells placed in two pairs, the filaments short, as wide as the anthers, staminodia 3; receptacle deep. Fruit initially enclosed in the cupule, at maturity either 2/ exserted or almost completely enclosed in the cupule. The new genus Sextonia is readily recognized by having clustered leaves and flowers with unequal tepals, characters already mentioned by Rohwer et al. (1991). The differences in wood and bark anatomy between Ocotea and Sextonia (as O. rubra) were amply discussed by Richter (1981), and indeed the main reason that Rohwer et al. (1991) did not describe a new genus to accommodate O. rubra was their reluctance to describe another monotypic genus. In a genus as large as Ocotea it is not surprising to find individual species or groups of species that differ in one or more morphological characters from the rest of the species, and finding such differences is not a sufficiently strong argument for describing a new genus. However, when such morphological differences are supported by differences in wood and bark anatomy the argument for a new genus is stronger. Three reasons made me consider the generic status of 0. rubra again. The first is the recent discovery of an undescribed species closely related to O. rubra, sharing with it the clustered leaves and flowers with unequal tepals, but differing in having pubescent flowers and racemose inflorescences. This new species has wood and bark anatomy similar to O. rubra. Describing this species in Ocotea would clearly be incorrect. The second argument is that during a study of the embryology of Lauraceae (Heo et al., in prep.) Ocotea rubra was found to differ clearly from the other four investigated species of Ocotea in having the mature embryo sac protruding from the nucellus, a character state otherwise only found in Beilschmiedia, Caryodaphnopsis, Cryptocarya, Endiandra, and Potameia, but lacking in genera considered closely related to Ocotea, such as Aiouea, Aniba, Cinnamomum, Licaria, Mezilaurus, and Nectandra. The third is that the inflorescences of the two species of Sextonia are different from those found in Ocotea. In Ocotea the flowers are arranged in cymes, with the lateral flowers of a cyme strictly opposite. In Sextonia rubra, however, the flowers are not arranged in cymes. Frequently the ultimate branching of the inflorescences appears racemose and flowers are not strictly opposite. The inflorescence types of Lauraceae and their importance for the suprageneric classification are discussed in detail by van NovoN 7: 436-439. 1997. This content downloaded from 157.55.39.151 on Thu, 07 Jul 2016 05:31:01 UTC All use subject to http://about.jstor.org/terms Volume 7, Number 4 van der Werff 437 1997 New Genus of Lauraceae

A New Species of Ocotea (Lauraceae) from the Serra do Espinhaço, Brazil

Ocotea oppositifolia, from the Serra do Espinhago, Bahia-Minas Gerais, Brazil, is described as new. It can be distinguished from the other neotropical species in the genus by the combination of its opposite leaves, pit domatia, and double-rimmed cupules. Ocotea, with more than 300 species, is one of the larger genera of Lauraceae and is known from the Neotropics, Madagascar, and tropical Africa. It is the largest genus of Lauraceae in the Neotropics, distributed from Mexico to Argentina. According to van der Werff (1991), the genus is extremely variable and sometimes thought to be a catchall for lesser known neotropical laurels. The species of this genus are characterized by the paniculate or racemose inflorescences, six equal tepals, nine stamens, anthers with four pollen sacs arranged in two rows, two small, globose glands at the base of each innermost stamen, and fruits with flat or cupshaped cupules. Nearly all the neotropical species of this genus have alternate or clustered leaves. However, some collections from Brazil were recently discovered to have opposite leaves. Some of these are treated as Ocotea sp. in van der Werff (1995). Besides the opposite leaves, the specimens have pit domatia and double-rimmed cupules, and the combination of those characters distinguishes them from all the other neotropical Ocotea species. Ocotea oppositifolia S. Yasuda, sp. nov. TYPE: Brazil. Bahia: Seabra, in a forest disturbed in some areas, with woody lianas, 900 m alt., 13 Feb. 1987 (fl), J. R. Pirani et al. 2000 (holotype, MO). Figure 1. Species haec ab aliis speciebus neotropicis differt foliis oppositis et domatiis foveatis et cupulis diplomarginatis. Small tree or shrub, 2-6(-12) m tall. Twigs terete, with a few appressed hairs, soon glabrescent. Terminal bud with appressed hairs. Leaves opposite, elliptic, 6-13 x 2-5 cm, the base and apex acute, firmly chartaceous, glabrous, glossy above, pinnately veined; lateral veins 8-12 pairs, the midrib, lateral veins, and reticulation immersed on both surfaces, or slightly raised below; pit domatia sometimes present in the axils of the secondary veins near the base, with straight hairs along the edges. Petioles 0.5-1 cm long, flat above. Inflorescences in the axils of the leaves or rarely around bracts, racemose, rarely paniculate, 3-6 cm long, with some appressed hairs. Pedicels pubescent, to 5 mm long, with an ovate-elliptic bract ca. 2.5 mm long at the base. Flowers bisexual, creamy or green, aromatic, 3-4 mm long including the slightly narrowed base. Tepals 6, equal, ovate, 2.0-3.0 X 1.52.2 mm, the outer surface with some appressed hairs or nearly glabrous, the inner surface with erect hairs, the inner surface of the inner tepals more densely so. Stamens 9, all 4-celled and the cells arranged in two rows, the anther 0.7-0.9 mm long, papillose on the apex, the filament 0.3-0.4 mm long, pubescent; outer 6 stamens with introrse cells, inner 3 stamens with extrorse cells, each of the inner stamens with 2 glands attached near the base. Staminodia 3, ca. 0.7 mm long, sagittate or stipitiform, pubescent. Ovary globose, ca. 0.7 mm diam., glabrous; style ca. 1.2 mm long, glabrous. Infructescences with few fruits, glabrous, rarely sparsely pubescent, 4-6 cm long. Fruits ellipsoid to ovoid, 2-2.5 cm long, ca. 1.4 cm wide (when dried), glabrous. Cupules olive-green, cup-shaped, ca. 2 cm wide, ca. 1.5 cm deep, glabrous, the outside smooth or slightly ridged, double-rimmed, the outer rim erect, slightly longer than the inner rim. Ocotea oppositifolia is known from the Serra do Espinhago, at about 1000 m in elevation. According to Harley (1995), the vegetation of this region is categorized as cerrado or campo rupestre: cerrado is a seasonal savanna woodland formation with medium to low trees and shrubs, characteristic of a huge area of southeast, central, and parts of western Brazil; campo rupestre is a unique vegetation of the upper levels of the Serra do Espinhago, where outcrops of usually highly acidic rocks inNovoN 6: 484-486. 1996. This content downloaded from 157.55.39.185 on Thu, 26 May 2016 06:00:17 UTC All use subject to http://about.jstor.org/terms Volume 6, Number 4 Yasuda 485 1996 Ocotea oppositifolia from Brazil

A Key to the Genera of Lauraceae in the New World

A Key to the Genera of Lauraceae in the New World

A New Genus of Lauraceae from Costa Rica, with Comments on Problems of Generic and Specific Delimitation Within the Family

Povedadaphne quadriporata is described and illustrated. Its possible relationships are suggested. The problems of specific and generic delimitation in Lauraceae are discussed from the viewpoint of a study of Costa Rica's nearly 100 species.

Dahlgrenodendron, a remarkable new genus of Lauraceae from Natal and Pondoland

A reappraisal of the taxonomic relationships of the southern African tree, Beilschmiedia natalensis J.H. Ross, proved it to be wrongly placed in the genus Beilschmiedia Nees. Its mature fruit is completely covered by the accrescent hypanthium, whereas Beilschmiedia (and the tribe Perseeae) is characterized by a completely deciduous perianth. Since it does not fit well with any of the existing lauraceous genera, a new genus, Dahlgrenodendron J.J.M. v.d. Merwe & Van Wyk, and new combination, D. natalense (J.H. Ross) J.J.M. v.d. Merwe & Van Wyk, are proposed. The pollen is most distinctive and decidedly different from anything known in Lauraceae. Grains are free, radially symmetrical, para-isopolar, ± spindle-shaped prolate (when dry), atreme, with a wall ornamentation of striae alternating with prominent ± parallel ridges. Dahlgrenodendron is further characterized by opposite leaves, fruit with an endocarp consisting of a palisade of columnar sclereids which develop from the ovary wall, and 2-celled anthers. It is tentatively related to the tribe Cryptocaryeae, subtribe Cryptocaryineae and compared with Cryptocarya R. Br. and Ravensara Sonn. — the two genera currently constituting this subtribe. D. natalense is an exceedingly rare forest species confined mainly to the southern Natal/Pondoland sandstone region. With the total number of individuals probably not exceeding 200, it is considered an ancient relict on the brink of natural extinction.

KARYOLOGICAL STUDIES IN SOME SPECIES OF LAURACEAE

SummaryThe chromosomes of sixteen species of nine genera of Lauraceae were studied morphologically at interphase, prophase and metaphase. The chromosomes of Cassytha filiformis were found to show different morphological characteristics in comparison with the other fifteen species, although the basic number of its chromosomes was the same, i. e., x = 12. The karyomorphological evidence in these species coincides with the proposal of Melchior (1964) to divide the Lauraceae into two subfamilies, Lauroideae and Cassythoideae.