A New Species of Trillium (Melanthiaceae) from Central Georgia and its Phylogenetic Position in subgenus Sessilium

Abstract

Abstract—Analysis of molecular phylogenetic data was used to reveal the existence of a novel species of Trillium subgen. Sessilium. Trillium delicatum sp. nov. differs from the two other low-growing species of the subgenus, T. decumbens and T. reliquum, in features such as straight stems and dung-scented flowers. It occurs in wet floodplain forests in the Oconee and Ocmulgee river drainages in central Georgia, and has a distinct floral scent compared to the wide spectrum in Trillium. The molecular phylogenetic results based on four markers (nuclear ribosomal ITS and plastid trnH-psbA, trnL-trnF, and rpl32-trnL spacers) included samples of all species of the subgenus, and documented the distinctiveness of T. delicatum as a distinct taxon and also provided resolution of species relationships that suggested that the subgenus originated in southeastern North America with two migrations to western North America. The molecular results also suggested the need for closer examination of T. cuneatum and T. lancifolium, and also to assess whether T. decipiens and T. underwoodii are distinct species. Based on the few known populations and susceptibility to damage by hogs, Trillium delicatum is a rare species requiring protection.

Taxonomic insights from floral scents of western North American sessile‐flowered Trillium

“…In 1975, Freeman published his revision of the Trillium subgenus Phyllantherum (referring to the sessile Trillium ; currently subgenus Sessilia ), where he described T. albidum , T. angustipetalum , and T. kurabayashii as distinct species from T. chloropetalum (Goodspeed and Brandt, 1916; Gates, 1917; Abrams, 1940; Peck, 1961; Munz, 1968; Freeman, 1975). Despite the apparent need for further clarification within this group, few phylogenetic analyses have since been conducted on Trillium (Kawano and Kato, 1995; Osaloo and Kawano, 1999; Farmer and Schilling, 2002; Schilling et al, 2019). Among the analyses, phylogenetic relationships of the western sessile Trillium to one another and the eastern taxa either vary or remain unresolved.…”

A revised subgeneric classification of Trillium (Parideae, Melanthiaceae)

“…(References:Case 2003, Case & Case 1997, Freeman 1975, Fukuda et al 1996, Gaddy 2008, Liang & Soukup 2000, O'Neill et al 2020, Patrick 1984, Samejima & Samejima 1987, Schilling et al 2013, Schilling et al 2017, Schilling et al 2019, Weakley 2020.TrilliumLinnaeus (1753: 339), nom. cons.Type:-Trillium cernuum L. (1753: 339) Trillium L. subgen.…”

A step‐by‐step protocol for meiotic chromosome counts in flowering plants: A powerful and economical technique revisited

“…A traditional way to observe chromosome number (a “chromosome count”), morphology, and pairing behavior is through a chromosome “squash.” Cells undergoing meiosis or mitosis are isolated, stained, and flattened, allowing condensed chromosomes to be observed and counted. Although chromosome counts continue to be reported (Cheema et al., ; Sadeghian et al., ; Schilling et al., ), it has been suggested that fewer young researchers are being trained in these methods (Goldblatt, ). This has contributed to a recent decline in published chromosome counts and an even sharper reduction in the number of publications per year providing these new data.…”