Tropaeolaceae: 681. TROPAEOLUM TRICOLOR

Tropaeolum tricolor Sweet is described and illustrated. Its history and distribution in the wild are discussed and notes on cultivation are given.     

938. SALVIA RAYMONDII SUBSP. MAIRANAE

The habitat and discovery of Salvia raymondii is described and the distinctions between the type subspecies and subsp. mairanae are discussed. Subsp. mairanae is illustrated and notes on its cultivation are provided.     

830. NERINE LATICOMA SUBSP. HUTTONIAE

The South African geophyte Nerine laticoma (Ker Gawl.) T. Durand & Schinz subsp. huttoniae (Schönland) Traub from the Eastern Cape is described and reinstated at subspecific level, accompanied by details of its history, taxonomy, life cycle, distribution and habitat.     

INFLORESCENCE DEVELOPMENT IN TWO ANNUAL TEOSINTES: ZEA MAYS SUBSP. MEXICANA AND Z. MAYS SUBSP. PARVIGLUMIS

The ontogeny of tassels and ears in two annual Mexican teosintes, Zea mays subsp. mexicana and Z. mays subsp. parviglumis, was examined using scanning electron microscopy and light microscopy. Ear development in these annual teosintes follows a pattern previously described as leading to the bisexual mixed inflorescence in Z. diploperennis. Common bud primordia are initiated in the axils of distichously arranged bracts along the ear axis. These common primordia bifurcate to form paired sessile and pedicellate spikelet primordia. Development of pedicellate spikelets is arrested leaving the sessile spikelets, along with the adjoining rachis segment, to form solitary grains enclosed within cupulate fruitcases. Development of the central tassel spike is similar to that previously described in the Z. diploperennis tassel, except that the first formed axillary bud primordia form precocious tassel branches. The origin of these tassel branches suggests a possible mechanism for the transition from a distichous spike, characteristic of teosinte, to a polystichous spike, typical of maize.     

A NATURE PRINT OF PETASITES JAPONICUS SUBSP. GIGANTEUS

Summary.  A very large nature print of Petasites japonicus (Sieb. & Zucc.) Maxim. subsp. giganteus Kitam., executed by Professor Keisuke Ito, was recently rediscovered in the collections of the Library, the Royal Botanic Gardens, Kew. The subject of nature prints is discussed, as are attempts to reproduce such a print, and a short discourse on the artist, Prof. Ito, is given. The confusing taxonomic history of Petasites japonicus subsp. giganteus is discussed. The plant is described and illustrated along with notes on its distribution and ecology; cultivation notes and indications of current uses are provided.     

A FIELD STUDY OF THE CALFBIRD PERISSOCEPHALVS TRICOLOR

The Calf bird Perissocephalus tricolor was studied in the Kanuku Mountains of southern Guyana for three months (January-April 1970), during which time almost daily visits were paid to a lek of four adult males. The adult males owned perches about 30 ft up in understorey trees, where they displayed and called throughout much of the day. Four immature males also visited the lek, particularly in the morning and evening. The immatures also wandered, feeding and occasionally calling together, over an area of forest of approximately 3 miles by half a mile. There was a hierarchy among the adult and immature males, the dominant males owning the most coveted perches at the lek. The male's most far-reaching call, the “moo call”, is a co-operative advertising call, in that birds calling together adjust the timing of their calls so as to follow each other and not overlap. The adult males perform a number of silent agonistic displays on their lek perches. Periodically, adult and immature males and sometimes a female invade the vicinity of a lek perch, usually that of the dominant male. Once a female was briefly mounted by the dominant male on his lek perch during an invasion. On other occasions females visited the lek but no mating occurred. The food of the males attending the lek was recorded by the daily collection of a total of 2,500 regurgitated fruit seeds (mostly drupes) from below the perches. Males also regularly take insects, but in smaller quantities. Three nests were found. The nest is an extremely light structure built entirely of fine twigs. A single egg was laid in each nest. All the nests (and two old ones) were within half a mile of the lek. Two of the nests were only 5 yards apart and the eggs were laid in them within 10 days of each other. The incubation period at one nest was 26–27 days and the fledging period approximately 27 days. The chick on hatching was covered in bright orange-chestnut down. It was fed mostly on insects (predominantly Orthoptera) brought by the female in her beak. There was no evidence of a male attending the nest. The Calfbird's nesting and lek behaviour is compared with that of other species of Cotingidae.     

地丁化学成分的研究

从紫花地丁中首次分得四个有机酸,一个酰胺和一个黄酮甙,其中二十四酰对羟基苯乙胺为一新化合物。     

POLLINATION IN LUPINUS NANUS SUBSP. LATIFOLIUS (LEGUMINOSAE)

Floral morphology and phenology and the timing of stigmatic receptivity and pollen viability were studied to elucidate the mechanisms by which self-pollination in Lupinus nanus subsp. latifolius is minimized under natural conditions. Pollen germination and pollen tube growth suggest that a physiological self-incompatibility system does not exist. Instead, self-pollination is minimized by protandry and by a collar of peristigmatic hairs, which initially inhibit access of autologous pollen to the stigma. These hairs subsequently wilt, permitting self-pollination of unvisited flowers. Pollen germinates in vivo one day before substantial metabolic enzyme activity can be detected. Citric acid cycle enzymes are not detectable in pollen, but those of anaerobic metabolism are. Beginning on the second day postanthesis, stigmatic secretions exude from weak areas on lateral walls of the elongate epidermal papillae, welling up in the interstices between these cells. This contrasts with the stigmas of other papilionoid legumes, in which secretions accumulate beneath the cuticle covering the stigmatic cells, and the often-thin cuticle must be ruptured before pollen and exudate can come into contact.     

THE FATE OF VIOLA SEEDS DISPERSED BY ANTS

Experimental plantings of the seeds of the two species Viola odorata and V. hirta were carried out to determine relative importance of three effects of myrmecochory: 1) clumping of seeds, 2) scarification of the testa and elaiosome removal, and 3) relocation into ant nests. The study site was a beech-larch wood in southern England. Data show that clumping slightly reduces seedling emergence, scarification and elaiosome removal slightly enhances it, while the nest environment significantly increases the rate of seedling emergence. Only the last effect is statistically significant. Seedlings from nests have larger first adult leaves. The possible impact of ant manipulation of seeds on seedling recruitment into myrmecochorous populations is discussed.