Two new species and a new combination in Frantzia (Cucurbitaceae)

The monotypic genusPolakowskia is reduced to a section ofFrantzia. Two new species from Costa Rica,F. villosa andF. talamancensis, are described. The new nomenclatural combination,F. tacaco (Pittier) Wunderlin, is proposed.     

Two new species and a new combination in Houstonia (Rubiaceae) from Mexico

Houstonia sharpii andH. kingii are described from Mexico. The new combinationH. xestosperma is proposed.     

Two new Agave species (Agavaceae) from central Arizona and their putative pre-Columbian domesticated origins

Recent fieldwork in central Arizona resulted in the discovery of two agaves that display low seed set, reproduce mainly by vegetative means, have restricted distributions, and cannot be readily assigned to any existing species. These agaves are closely associated with archaeological structures and features and can be found growing with other previously described pre-Columbian Agave domesticates. Herein we describe Agave verdensis and A. yavapaiensis, two species that can be placed within Gentry’s informal Ditepalae Agave group, and propose that they are clonal relict domesticates. The two species have affinities with A. chrysantha, A. shrevei, and A. delamateri, the latter also a central Arizona pre-Columbian domesticate. We provide a key to distinguish these species from other agaves in central Arizona and adjacent northern Mexico with which they may be confused. The discovery of these two new species brings the total number of putative Arizona Agave domesticates to five species.     

Agave rzedowskiana, a new species in subgenus Littaea (Agavaceae) from western Mexico

Agave rzedowskiana is described and illustrated from the states of Sinaloa and Jalisco, Mexico. This species is a member of subgenusLittaea (Tagliabue) Baker “groupStriatae” of Baker. It is compared withA. petrophila García-Mend. & E. Martínez andA. dasylirioides Jacobi & Bouché.

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Resumen  Se describe e ilustraAgave rzedowskiana de los estados de Sinaloa y Jalisco, México. La especie pertenece al subgéneroLittaea (Tagliabue) Baker “Grupo Striatae” de Baker. Se le compara conA. petrophila García-Mend. & E. Martínez yA. dasylirioides Jacobi & Bouché.

     

A mathematical model that uses Gaussian distribution to analyze the germination of Manfreda brachystachya (Agavaceae) in a thermogradient

Germination of nondormant seeds of Manfreda brachystachya (Agavaceae) was analyzed at temperatures ranging from 11–35°C. Maximum germination (95%) occurred at 25°C. An exponential sigmoid relationship was found between time and cumulative germination. Germination rate for every subpopulation (10–90% germination) was estimated by means of a normal distribution analysis. The kurtosis indicated die amplitude of the range of temperatures where the highest germination rates were concentrated, and the skew indicated sharply inhibitory temperatures in the range of temperatures used. Based on analysis of the normal distribution models for each subpopulation, we calculated a theoretical function which described germination rate over the temperature range considered: F(T,χ) = A × exp[−B(C−1)²], where A is the function that describes germination rate for each subpopulation (characterized by the percentage [χ] at optimal temperature); B is a shape parameter, 1/(σG²); and C is the ratio between each germination temperature (T) and the optimal germination temperature. The Gaussian curves were used to calculate thermal time, and base and ceiling temperatures. Germination thermal time ranged from 1 333 to 2 373°C h, and base and ceiling temperatures were 10.44 ± 0.7°C and 39.54 ± 0.7°C, respectively. There was a linear relationship between thermal time and cumulative percentage of germination of the subpopulations. Based on fitted curves for each subpopulation, the use of a general model for all the subpopulations has been proven: F8 = A × exp[−5.9437(C−1)²], where changes in the curves for each subpopulation depended on temperature only.     

A mathematical model that uses Gaussian distribution to analyze the germination of Manfreda brachystachya (Agavaceae) in a thermogradient

Germination of nondormant seeds of Manfreda brachystachya (Agavaceae) was analyzed at temperatures ranging from 11–35°C. Maximum germination (95%) occurred at 25°C. An exponential sigmoid relationship was found between time and cumulative germination. Germination rate for every subpopulation (10–90% germination) was estimated by means of a normal distribution analysis. The kurtosis indicated die amplitude of the range of temperatures where the highest germination rates were concentrated, and the skew indicated sharply inhibitory temperatures in the range of temperatures used. Based on analysis of the normal distribution models for each subpopulation, we calculated a theoretical function which described germination rate over the temperature range considered: F(T,x) = A × exp[-B(C−1)²], where A is the function that describes germination rate for each subpopulation (characterized by the percentage [x] at optimal temperature); B is a shape parameter, 1/(σ²); and C is the ratio between each germination temperature (T) and the optimal germination temperature. The Gaussian curves were used to calculate thermal time, and base and ceiling temperatures. Germination thermal time ranged from 1333 to 2373°C h, and base and ceiling temperatures were 10.44 ± 0.7°C and 39.54 ± 0.7°C, respectively. There was a linear relationship between thermal time and cumulative percentage of germination of the subpopulations. Based on fitted curves for each subpopulation, the use of a general model for all the subpopulations has been proven: F8 = A × exp[−5.9437(C−1)²], where changes in the curves for each subpopulation depended on temperature only.     

云南龙血树属(龙舌兰科)一新种——深脉龙血树

描述了龙血树属Dracaena一新种--深脉龙血树D. impressivenia Y. H. Yan &; H. J. Guo, 并绘了线图。该种产于中国云南盈江县, 与矮龙血树D. terniflora Roxb.叶形相似, 但侧脉深陷, 总状花序上具许多每6-9朵簇生的花, 苞片暗红色, 花被伸直, 长3-3.5 cm, 可与后者明显区别。     

Neotropical Copestylum (Diptera,Syrphidae) breeding in Agavaceae and Cactaceae including seven new species

We studied 42 species of saprophagous, Neotropical Copestylum (Diptera, Syrphidae) reared from decaying Cactaceae and Agavaceae. Thirty‐three species were reared during fieldwork in Bolivia, Costa Rica, Ecuador, Mexico, Peru, and Trinidad from 1998–2007. Nine species came from museum and private collections. Seven were new species. We describe these new species and the third stage larva and/or puparium and breeding sites of 40 species. Not described are two apparent species related to Copestylum apicale (Loew, 1866) reared from Cactaceae. Resolution of their status was beyond the scope of this paper but reference is made to their distinctive larval morphology. Based on early stage characters all reared species can be placed in ten species groups, all but three of which have been recognized previously on the basis of adult characters. A high level of congruence was found between adult and larval characters in terms of these species groups. Eight of the groups appear to be related closely and may represent a monophyletic lineage within Copestylum that has diversified in xeric habitats. Early stage morphology varied within and amongst groups but two trends in functional morphology are recognizable. One trend is towards feeding in watery decay and the other towards feeding in firmer decay. The latter trend is characterized by species that scoop food and use grinding mills in their head skeletons to break it up. They also have armoured thoraces with varying arrangements of sclerotized spicules or stiffened setae for gripping and protection during tunnelling, a short anal segment, and a short posterior breathing tube for protecting the openings. The former trend is characterized by species with opposite and contrasting features. They filter food and have well‐developed pre‐oral setal filters but they lack grinding mills or only have poorly developed grinding mills. They have reduced thoracic armature, elongate anal segments, and posterior breathing tubes which facilitates simultaneous feeding and respiration. Comparison with 23 Copestylum species reared from bromeliads (Bromeliaceae) suggests a common pattern of diversification in that species groups with the largest body sizes are more specialized.     

A new species and a new combination in the genus Eucrosia (Amaryllidaceae)

Eucrosia dodsonii is described from Ecuador andLeperiza eucrosioides Baker is combined withEucrosia asE. brachyandra.     

A new species and a new combination in Zanthoxylum (Rutaceae) from Brazil

A new species,Zanthoxylum hamadryadicum, is described, illustrated and compared to its closest relatives. It is unique in its small leaves and leaflets, which are densely stellate-pilose, and its short racemes crowded on new shoots with 4-merous flowers. A new combination,Zanthoxylum hasslerianum (Chodat) Pirani, and some new synonyms among Brazilian species are proposed.     

Agave turneri (Agavaceae), a new species from northeastern Baja California, Mexico

Agave turneri, a new species of Agave from the Sierras Cucapá and El Mayor in northeastern Baja California, Mexico, is a medium-sized species that does not produce offsets, has a relatively short and narrow panicle, and has a distinctive flower structure. The closest relatives to this new species are Agave moranii, which occurs approximately 200 km to the south of the type locality, and A. deserti var. simplex, which occurs in Arizona and California. This new species is a narrow endemic restricted to specific granodiorite and tonalite habitats in a hyperarid environment. Agave turneri appears to be a critically endangered owing to its habitat preference for specific types of granite in the Sierra Cucapá, threats due to prolonged drought and global change, and its close proximity to the Mexicali metropolitan area.     

A new species and a new combination in Stelis (Pleurothallidinae-Orchidaceae) from South America

Stelis duckei, of the Crocodeilanthe group, is described from the state of Ceará, Brazil. The new species is morphologically similar to S. speciosa, but can be distinguished by its longer ramicauls, wider leaves, and obtuse lip with a ridge-like callus at the base. The new combination Stelis speciosa is also provided here.     

A new species and a new combination in western North American Silene (Caryophyllaceae)

Silene nachlingerae is described, illustrated, and compared toS. aperta. The similarly floweredS. invisa is considered to be closely related toS. bernardina, and especially to its var.rigidula (Robinson) Tiehm, comb nov.     

Three new species and a new combination in Arracacia Bancroft (Umbelliferae/Apiaceae)

Three species ofArracacia—A. hintonii, A. colombiana, andA. tillettii—from Mexico, Colombia, and Venezuela, respectively, are described as new, andCoulterophytum brevipes Coulter & Rose is transferred toArracacia asA. quadrifida, nom. nov. and comb. nov.     

Two new species and one new combination of Agaricales from Japan

 Two new species and one new combination of Agaricales are described and illustrated from eastern Honshu, Japan, and Ishigaki Island, southwestern Japan: (1) Gymnopus oncospermatis comb. nov. (subsection Vestipedes of section Vestipedes), new to Japan, has pale brown to whitish, collybioid basidiomata with very close lamellae, and forms a distinct white extensive mycelial mat on the dead leaf bases of the palm Satakentia liukiuensis in Ishigaki Island; (2) Hydropus aurarius sp. nov. (subsection floccipedes of section floccipedes), forming clitocyboid basidiomata with a dark brown furfuraceous pileus and stipe and vivid yellow lamellae, found on fallen dead twigs in oak forests; and (3) Tylopilus castanoides sp. nov. (section Oxydabiles), forming medium to large, reddish-brown basidiomata with a minutely scurfy-punctate stipe, found in Carpinio quercion forests. Received: May 20, 2002 / Accepted: July 17, 2002 Acknowledgments I am grateful to Dr. Yousuke Degawa (KPM) for allowing the specimens cited to be kept in the Kanagawa Prefectural Museum of Natural History. Thanks are also owed to Mr. Sadayoshi Uehara, Mr. Wakao Ikeda, Mrs. Youko Ando, Dr. Yasushi Shibata, and Mr. Yasuhiko Goto for provision of specimens. Correspondence to:H. Takahashi     

A new combination and a new species in the lichen genusCatapyrenium (lichenizedAscomycetes,Verrucariaceae)

Catapyrenium pyrenaicum is described as new from northern Spain and adjacent France, and the new combinationCatapyrenium velebiticum is made. The new species differs fromC. velebiticum mainly in its laminal pycnidia. Remarks on taxonomy, ecology, and distribution of the species are given.     

Two new taxa and a new combination for Stipa (Gramineae: Stipeae) in Tunisia

Two new taxa in Stipa L. Sect. Leiostipa Dumort., S. alba and S. letournexii ssp. ignea , are described from southern Tunisia (northern Africa). In addition, the S. letournexii complex is reviewed and a new combination, S. letournexii ssp. tunetana (H.Scholz) F.M. Vázquez, is presented.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 439–444.     

Two new species and a new series of Elatostema (Urticaceae) from China

The new series Elatostema section Elatostema series Albopilosoides Q.Lin & L.D.Duan (Urticaceae) is described, and two new species of Elatostema, namely Elatostema albopilosoides Q.Lin & L.D.Duan and Elatostema purpureum Q.Lin & L.D.Duan. from south Guizhou province, south‐west China are described and illustrated. Both species were found growing only at the base of a large limestone chamber at an altitude of c. 800 m. Elatostema albopilosoides is morphologically similar to E. albopilosum W.T.Wang, but differs by having female inflorescences with peduncles 10–60 mm long (0–1.5 mm long in E. albopilosum) and receptacles 7–27 mm long, 7–24 mm wide (E. albopilosum: 1–4 mm long and 1–3 mm wide). Elatostema purpureum is also morphologically similar to E. albopilosum, but has stipules 5–6 mm long, 0.8–1.5 mm wide (4–7 mm long, 1.5–2.8 mm wide in E. albopilosum) and leaf blades obliquely elliptical to obliquely oblong‐obovate, 3.5–7.5 mm long and 1.5–2.5 mm wide (obliquely narrowly oblanceolate‐oblong, 12–17 cm long, 3–5 cm wide in E. purpureum:). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 674–680.