Abstract Detail

Floristics & Taxonomy

Maldonado Borja, Maria Guadalupe [1], Cerros-Tlatilpa, Rosa [1], Galván-González, Luis Gil [1].

The genus Struthanthus Mart. (Loranthaceae) in Mexico.

Struthanthus Mart. is one of the 77 genera on the family Loranthaceae. It is a Neotropical hemiparasite distributed from northern Mexico to Argentina, it has approximately 60 to 70 species, Villaseñor (2016) records 22 species for Mexico. Struthanthus has scandent, leafy, and glabrous plants, small 5- or 6-merous, unisexual, greenish-white flowers (except S. interruptus (Kunth) G. Don with bisexual flowers). Inflorescences are axillary, indeterminate, raceme, spike, or capituliform of 2-15 pairs of triads opposite on the floral axis. Fruits are fleshy berries with a single seed, covered by a sticky layer of viscin, that adheres to the branches of its host. Some species are epiparasitic, requiring another parasitic plant to survive. Struthanthus exhibits difficulties in its identification since many of its species have been described only with male or female specimens, or specimens with infructescences. Struthanthus and Cladocolea Tiegh., are closely related and shared several morphological similarities, however, the former has flower subunits in dyads or triads, while the latter has monads. A floristic inventory of the genus in Mexico is presented. An exhaustive literature review was carried out, specimens from national and international herbaria (CHAPA, CIIDIR, F, FH, HUAA, HUMO, K, MEXU, P, RSA, SLPM, UAMIZ, UAS, UC, US, USON, W, ZEA), were examined also specimens were collected on the field in the states of Chiapas, Guerrero, Jalisco, México, Michoacán, Morelos, Puebla, Colima, Oaxaca and Veracruz. A total of 1638 specimens were studied and correspond to 15 species; these are distributed in 24 states of Mexico. Seven species were excluded since three are synonyms and four belong to Cladocolea (2) and Phthirusa Mart. (2). Thirteen species are recorded for Chiapas and six states have a single species. Struthanthus orbicularis (Kunth) Eichler, is widely distributed from Mexico to Brazil. Six species are endemic to Mexico (S. condensatus Kuijt, S. crassipes Eichler, S. matudae Lundell, S. palmeri Kuijt, S. phaneroneurusStandl., and S. ramiro-cruzii Martínez-Ambr. & Soriano-Benítez). New epiparasitism cases are recorded, such as S. crassipes on Phoradendron sp., and S. interruptus on Phoradendron brachystachyum (DC.) Oliv. On other hand, S. interruptus has a great variety in leaf morphology even in a single individual, which complicates its identification. A species identification key for Mexico is included.

1 - Universidad Autonoma del Estado de Morelos, Facultad de Ciencias Biológicas, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor, 62209, Mexico

Keywords:
Loranthaceae
Floristics
Hemiparasites
Epiparasitic
Mistletoes.

Presentation Type: Poster
Session: P2, Floristics & Taxonomy Posters
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 5:00 PM(EDT)
Number: P2FT010
Abstract ID:865
Candidate for Awards:None