@article {20361, title = {Floral structure and ontogeny of Syndiclis (Lauraceae)}, journal = {PLoS ONE}, volume = {12}, year = {2017}, month = {10/2017}, pages = {e0186358}, abstract = {

Generic delimitation in the Beilschmiedia group of the Lauraceae remains ambiguous because flowering specimens of a few genera with confined distribution are poorly represented in herbaria, and a few floral characters important for taxonomy are still poorly known. Syndiclis is sporadically distributed in southwestern China, and is represented in the herbaria by only a few flowering specimens. We conducted field investigations to collect floral materials of four species and observed structures and ontogeny of the tiny flowers using both light microscopy (LM) and scanning electron microscopy (SEM). The results show that the genus Syndiclis possesses flowers with huge variation in both merosity and organ number. Flowers of the genus are dimerous, trimerous, or tetramerous, or have mixed merosity with monomerous and dimerous, or dimerous and trimerous, or trimerous and tetramerous whorls. The number of staminodes ranges from two to eight, depending on floral merosity, and on how many stamens of the third androecial whorl are reduced to staminodes. The staminodes of the fourth androecial whorl are comparable to the staminodes in Potameia, but the staminodes of the third androecial whorl of Syndiclis are relatively larger than the staminodes in Potameia. They are erect or curved inwards, covering the ovary. The anthers are usually two-locular, but rarely one-locular or three-locular. Each stamen of the third androecial whorl bears two conspicuous and enlarged glands at the base. The lability of floral merosity and organ number of Syndiclis may have been caused by changes of pollination system and loss of special selective pressures that are present in most Lauraceous plants with fixed floral organ number. This study furthers our understanding of variation and evolution of a few important characters of the Beilschmiedia group and provides essential data for a revised generic classification of the group.

}, doi = {10.1371/journal. pone.0186358}, author = {Zeng, Gang and Liu, Bing and David K. Ferguson and Rohwer, Jens G. and Yang, Yong} } @article {20280, title = {Origin and evolution of the unusual leaf epidermis of Caryodaphnopsis (Lauraceae)}, journal = {Perspectives in Plant Ecology, Evolution and Systematics}, volume = {16}, year = {2014}, month = {07/2014}, pages = {296-309}, chapter = {296}, abstract = {

We studied leaf epidermal anatomy of Caryodaphnopsis Airy Shaw, a genus disjunct between tropical Asia and tropical America, using light microscope and scanning electron microscope. We sampled 10 species of Caryodaphnopsis and 52 species of other Lauraceous genera. Our observations suggest that this genus possesses a unique lower leaf epidermis. Compared with other leaves of Lauraceae, this genus has an additional layer covering the lower leaf epidermis and the stomatal apparatus. The additional layer is either closed or poriferous/reticulate. The outer periclinal walls of the lower leaf epidermis protrude outside forming hollow domes or columns, and the distal endings of these domes or columns are expanded and fused, which forms the additional covering layer. Three different types are recognized in the genus: (1) the middle portion of the protuberances is not contracted and the distal endings are free or adnate to each other, with only limited space between the two layers; (2) the middle portion is slightly contracted in the outer part, the distal endings are fused, with more space between the two layers; (3) the middle portion is conspicuously contracted and elongated into columns, the distal endings are fused and it is roomy between the two layers. The structure of the leaf lower epidermis is reconstructed and illustrated for the first time. This unusual leaf lower epidermis of Caryodaphnopsis is derived in Lauraceae and is an autapomorphic character. Outward protrusions of the outer periclinal walls forming papillate protuberances surrounding the stomatal apparatus are also found in a few other genera including Neocinnamomum, a genus closely related to Caryodaphnopsis, but the distal endings of these protrusions are not expanded and connected. We hypothesize that the periclinal wall of the lower leaf epidermis has been gradually modified in Lauraceae, from a smooth pattern in most genera, to papillate pattern (e.g. Neocinnamomum), and to the double layered lower leaf epidermis in Caryodaphnopsis. The origin and evolution of this unique lower epidermis might have been related to the climatic cooling and aridification since the late Eocene.

}, author = {Zeng, Gang and Liu, Bing and van der Werff, Henk and David K. Ferguson and Yang, Yong} } @article {19994, title = {On the taxonomy of recent and fossil species of Laurus (Lauraceae)}, journal = {Botanical Journal of the Linnean Society }, volume = {68}, year = {1974}, pages = {51-72}, chapter = {51}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8339.1974.tb01747.x/abstract}, author = {David K. Ferguson} } @article {18726, title = {Homalanthus costatus Mai: a new Miocene fruit of Cinnamomum Schaeffer (Lauraceae)}, journal = {Palaeontographica. Abteilung B. Pal{\"a}ophytologie}, volume = {232}, year = {1994}, month = {05/1994}, pages = {155-174}, keywords = {Lauraceae; Cinnamomum; diaspores; Miocene; Europe}, author = {Pingen, M. and David K. Ferguson and Collinson, M. E.} }