Tristagma Poepp. (Amaryllidaceae, Allioideae) se caracteriza morfológicamente por la combinación de una espata compuesta por dos brcteas connadas en la base, un tubo floral que siempre cubre al ovario y filamentos estaminales dispuestos en dos series. Tanto la circunscripción genérica, como la de las especies de Tristagma ha sido fuente de confusión, principalmente debido a la dificultad de encontrar ejemplares de herbario completos, la floración temprana, la abundancia de taxones descritos o transferidos a Tristagma y la falta de una clave para las especies. Sobre la base de una exhaustiva revisión bibliogrfica y estudios morfológicos, se presenta una breve historia taxonómica del género, una descripción del mismo y se reconocen 12 especies, incluyendo su distribución geográfica, fenología, nuevas ilustraciones y una clave para las especies. Nuestra revisión incluye el estudio de ca. de 500 especímenes, la visita a 42 herbarios y la designación de un neotipo.

Asplenium L. is estimated to be the largest fern genus and is very prone to polyploidy and hybridization. We investigated the phylogenetic relationships of two geographically restricted complexes in the Mediterranean Basin, and searched for evidence of multiple and/or reciprocal origins of the allopolyploids. The A. obovatum Viv. and A. adiantum-nigrum L. complexes include a total of five diploid and four polyploid taxa and are linked by the tetraploid A. balearicum Shivas. We collected 36 new samples representing all nine taxa, from which we amplified five chloroplast regions. We also included sequences from GenBank and performed maximum likelihood (ML) and Bayesian inference (BI) analyses to identify multiple and reciprocal origins. We conducted a larger molecular dating analysis to assess relationships with the rest of Asplenium and estimate divergence times. This matrix included 137 species of Asplenium and three outgroups, including sequences previously published. All sequences of allotetraploids A. adiantum-nigrum and A. balearicum grouped with A. onopteris L., with no sign of reciprocal parentage, but possible evidence of multiple origins. The tetraploids A. foreziense Le Grand and A. billotii F.W. Schultz grouped with both respective parents, indicating probable multiple and reciprocal origins. The best supported case of reciprocal parentage is A. foreziense. In the larger analysis, the species studied resolve in two different clades that correspond to the two complexes, and the groups are not closely related, with a conservative estimate of 45.43 millions of years ago (Ma) for their divergence. There is evidence of multiple origins of all four allopolyploids, though only with strong support for one, and of reciprocal origins for two of the four allopolyploids, though again only one is well supported. Asplenium balearicum represents a hybridization event between members of clades whose ancestors diverged roughly 45 Ma, making this divergence one of the oldest to have descendants later produce hybrid offspring.

The pantropical genus Tectaria Cav. (Tectariaceae) is one of the largest fern genera. It has been estimated to contain ca. 210 mostly tropical species in Africa, the Americas, Asia, and the Indian Ocean and Pacific Ocean islands. Tectaria had perhaps been the most confusing fern genus in terms of its circumscription and phylogeny. Recent studies have recircumscribed Tectaria and resolved the relationships within the genus. However, no efforts have been made to propose an infrageneric classification of the genus based on molecular and morphological evidence. In the present study, we synthesize chloroplast and nuclear DNA evidence, morphology, and/or distribution information and divide Tectaria into four subgenera: Tectaria subg. Ctenitopsis (Ching ex Tardieu & C. Chr.) Li Bing Zhang & Liang Zhang (comb. & stat. nov.), Tectaria subg. Phlebiogonium (Fée) Li Bing Zhang & Liang Zhang (comb. & stat. nov.), Tectaria subg. Tectaria, and Tectaria subg. Tectaridium (Copel.) Li Bing Zhang & Liang Zhang (comb. & stat. nov.). The latter three are further divided into seven, two, and two sections, respectively. Sixteen generic names are synonymized to individual infrageneric taxa, while four generic names are only synonymized to Tectaria because of inadequate data. A key to the infrageneric taxa is given. A nomenclatural account of each infrageneric taxon is provided.

Lithospermum L. (Boraginaceae) includes approximately 60 species of which 43 occur in Mexico, with 32 endemic to the country. Through morphological and molecular investigations, the species of the genus are taxonomically revised. A broad generic circumscription is recognized and includes species traditionally recognized as members of Lithospermum as well as other New World Lithospermeae. Three new species are described from northern Mexico—Lithospermum chihuahuanum J. I. Cohen, Lithospermum kelloggianum J. I. Cohen, and Lithospermum tenerum J. I. Cohen—and each is known from only its type specimen. Lasiarrhenum confundum B. L. Turner is transferred to Lithospermum confundum (B. L. Turner) J. I. Cohen on the basis of flowers similar to those of Lithospermum trinervium (Lehm.) J. I. Cohen. The type for Pentalophus A. DC. is designated. Lectotypes are designated for Lithospermum albicans Greene [= Lithospermum incisum Lehm.], Lithospermum approximatum Brand [= Lithospermum distichum Ortega], Lithospermum breviflorum Engelm. & A. Gray [= Lithospermum incisum Lehm.], Lithospermum cobrense Greene, Lithospermum cognatum Greene ex Spengle [= Lithospermum multiflorum Torr. ex A. Gray], Lithospermum euryphyllum Brand [= Lithospermum oblongifolium Greenm.], Lithospermum galeottii Brand [= Lithospermum calycosum (J. F. Macbr.) I. M. Johnst.], Lithospermum gentianoides Brand [= Lithospermum obovatum J. F. Macbr.], Lithospermum hoyasense Brand [= Lithospermum calcicola B. L. Rob.], Lithospermum laevigatum Sessé & Moc. [= Lithospermum distichum Ortega], Lithospermum madrense Brand [= Lithospermum calcicola B. L. Rob.], Lithospermum matamorense DC., Lithospermum nelsonii Greenm., Lithospermum obtusiflorum Sessé & Moc. [= Lithospermum discolor M. Martens & Galeotti], Lithospermum sordidum Brand [= Lithospermum distichum Ortega], and Lithospermum spathulatum M. Martens & Galeotti [= Lithospermum distichum Ortega]. Lithospermum viride Greene is neotypified.

In subgenus Decaloba (DC.) Rchb. of Passiflora L., the section Xerogona (Raf.) Killip (Passifloraceae) is a group of herbaceous vines found in subtropical and tropical regions of the Americas. Primarily distributed in Central America, with a few also found in the West Indies and South America, the species of Passiflora sect. Xerogona are recognized by their unusual dehiscent capsular fruit, the absence of bracts and laminar nectaries, and their transversely grooved seeds. Passiflora tenella Killip is the only species included in Passiflora sect. Xerogona with a fruit that does not appear to be a capsule, but the shape of the leaves and the absence of floral bracts and laminar nectaries suggest affiliation with this section. Fifteen species, including two subspecies, are recognized within Passiflora sect. Xerogona. Passiflora cobanensis Killip is distinguished as two subspecies, P. cobanensis subsp. cobanensis and P. cobanensis subsp. brevipes (Killip) T. Boza, with the latter subspecies transferred from P. brevipes Killip. From previous species circumscriptions, this section contains two problematic species complexes for P. capsularis L. and P. rubra L. The morphological variation between and within these two species complexes was examined in this study, using Principal Component Analysis and correlation matrices of morphological characters, and this variation was studied throughout their distributional ranges. Passiflora capsularis is recognized as a single variable species. Two species are recognized within the P. rubra complex, based primarily on floral characters, as P. cisnana Harms and P. rubra. Passiflora cisnana is lectotypified.