Bertil Ståhl

Diversity and Distribution of Floral Scent

A list of 1719 chemical compounds identified from headspace samples of floral scent is presented. The list has been compiled from some 270 published papers, including analyses of 991 species of flowering plants and a few gymnosperms, a sample including seed plants from 90 families and 38 orders. The compounds belong to seven major compound classes, of which the aliphatics, the benzenoids and phenylpropanoids, and, among the terpenes, the mono- and sesquiterpenes, occur in most orders of seeds plants. C5-branched compounds, irregular terpenes, nitrogen-containing compounds, and a class of miscellaneous cyclic compounds have been recorded in about two-thirds of the orders. Sulfur-containing compounds occur in a third of the orders, whereas diterpenes have been reported from three orders only. The most common single compounds in floral scent are the monoterpenes limonene, (E)-β-ocimene, myrcene, linalool, α- and β-pinene, and the benzenoids benzaldehyde, methyl 2-hydroxybenzoate (methyl salicylate), benzyl alcohol, and 2-phenyl ethanol, which occur in 54–71% of the families investigated so far. The sesquiterpene caryophyllene and the irregular terpene 6-methyl-5-hepten-2-one are also common and occur in more than 50% of the families. Orchidaceae are by far the best investigated family, followed by several families known to have many species with strongly scented flowers, such as Araceae, Arecaceae, Magnoliaceae, and Rosaceae. However, the majority of angiosperm families are still poorly investigated. Relationships between floral scent and pollination, chemistry, evolution, and phylogeny are briefly discussed. It is concluded that floral scent chemistry is of little use for phylogenetic estimates above the genus level, whereas the distribution and combinations of floral scent compounds at species and subspecific levels is a promising field of investigation for the understanding of adaptations and evolutionary processes in angiosperms.

Maesaceae, a new primuloid family in the order Ericales s.l.

Evidence from morphology and molecular sequence data from three chloroplast genes, rbcL, ndhF, and atpB, have shown that the genus Maesa constitutes an evolutionary lineage separate from the other three primuloid families, Theophrastaceae, Myrsinaceae, and Primulaceae. The new family Maesaceae is here formally recognised, its taxonomic status being changed from a subfamily of Myrsinaceae. The new family comprises a single genus, Maesa Forssk., with some 100 species of trees or shrubs; it is diagnosed by characters such as flower pedicels with two bracteoles, a semi-inferior ovary, and indehiscent fruits with many seeds. A key to the major groups of primuloid taxa is presented.

Phylogeny of Theophrastaceae (Ericales s. lat.)

Morphological traits and sequences from two chloroplast genes, ndhF and trnL‐F (intron, 3′ exon, and spacer), have been used to investigate relationships in the Ericalean family Theophrastaceae. A total evidence parsimony analysis shows that the herbaceous genus Samolus is sister to all other Theophrastaceae. The latter are in turn divided into two major groups, one with Theophrasta, Neomezia, and Clavija and the other with Deherainia, Votschia, and Jacquinia. The representatives of Jacquinia are found in two separate well‐supported clades, one consisting of the white‐flowered species and the other of the mostly orange‐red‐flowered species, together with J. paludicola and J. longifolia, two aberrant species with whitish yellow flowers. Deherainia and Votschia group with the latter clade, which makes Jacquinia paraphyletic. We propose that J. paludicola and J. longifolia, together with the orange‐red‐flowered Jacquinia, be recognized as a separate genus, Bonellia. The sister taxa Theophrasta and Neomezia are confined to Hispaniola and Cuba, respectively. Within Clavija, which is the sister group of Theophrasta‐Neomezia, the only Antillean species, Clavija domingensis, is sister to all other species occurring in South and Central America. With the splitting of Jacquinia, Jacquinia s. str. is composed of species occurring in the Caribbean, which are mostly confined to the Greater Antilles, whereas Bonellia is composed of a mixture of Caribbean, Central American, and South American species.

A new species of Symplocos (Symplocaceae) from southern Ecuador

Abstract A new species from Ecuador, Symplocos limonensis, is here described and illustrated. It resembles Symplocos clethrifolia but differs by having larger leaves with evident (i.e., not concealed) areoles on lower surface, sessile inflorescences, smaller white corollas, and fewer stamens. The species is only known from three collections in the Andean forests of Morona-Santiago Province in southern Ecuador.

Cotton, E., Borchsenius, F. and Balslev, H. 2014. A revision of Axinaea (Melastomataceae). – Sci. Dan. B. Biol. Vol. 4. Det Kongelige Danske Videnskabernes Selskab, 120 pp. 200 DKK. ISBN 978-87-7304-385-1.

Cotton, E., Borchsenius, F. and Balslev, H. 2014. A revision of Axinaea (Melastomataceae). – Sci. Dan. B. Biol. Vol. 4. Det Kongelige Danske Videnskabernes Selskab, 120 pp. 200 DKK. ISBN 978-87-7304-385-1.