Abstract Detail

Systematics Section / ASPT

Meerow, Alan [1], van der Werff, Henk [2].

Pucara (Amaryllidaceae) reduced to synonymy with Stenomesson on the basis of nuclear and plastid DNA spacer sequences, and a new related species of Stenomesson.

Meerow et al. (1986) described the first known occurence of mature pollen in tetrads within the Amaryllidaceae for a species they determined as Stenomesson elwesii Macbr. from collections by Paul Hutchinson. Meerow later had the opportunity to examine the type of S. elwesii [now Clinanthus elwesii (Macbr.) Meerow] at Kew, and it became obvious that the name was misapplied by Meerow et al. (1986). The identity of the Hutchinson collections remained unknown. While it clearly bore resemblance to a species of Stenomesson sensu stricto (Meerow et al. 2000), the palynological apomorphy and the low elevation of the collection were unusual.
New collections from the Department of Amazonas in Peru in 1999 and 2001 were identified as representing both this unidentified species and the sole species of Pucara Rav., P. leucantha Rav., allowing more detailed study. We observed that P. leucantha has leaf morphology similar to the undescribed species, and also releases its pollen in tetrads. In this paper, we show that the phylogenetic position of these two species based on DNA sequences leave little doubt that the genus Pucara should not be recognized as distinct from Stenomesson (sensu Meerow et al. 2000). We further describe the misidentified taxon as a new species of Stenomesson, S. chloranthum, allied to the erstwhile P. leucantha. Both of these species release their pollen in tetrads, unique within Amaryllidaceae, and have tri-lobed stigmas, unique within Stenomesson.

1 - U.S. Department of Agriculture,, Agricultural Research Service,, 13601 Old Cutler Road, Miami, Florida, 33158, USA
2 - Missouri Botanical Garden, PO Box 299, St. Louis, Missouri, 63166-0299, USA

Keywords:
Amaryllidaceae
Andes
Bayesian analysis
chloroplast DNA
cladistic analysis
Classification
ITS
molecular phylogeny
molecular systematics
monocot.

Presentation Type: Poster
Session: 32-76
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM
Abstract ID:751