Survey of the vascular plants Why we put what where and to determine families
Outline • How is relatedness among plant families determined? • Different representative phylogenetic trees • Using a synoptic key • Tips for learning plant families
How were plant families related? • Relatedness among plant families was determined in the past primarily by floral traits • Linnaeus used plant sexual organs as a primary basis in distinguishing families and genera.
Family Relatedness Now • With the advent of molecular technology, there are many other ways to determine relatedness. • Mostly, phylogenetic work is now done according actual differences in the DNA chloroplast genes • The goal is to always create a monophyletic group
Monophyletic Groups • A group containing only and all descendents of a common ancestor, and it is often characterizable by apomorphies, that is, shared, derived characters that appeared in the ancestral lineage or stem clade of that monophyletic group.
http://www.mobot.org/MOBOT/research/APweb/welcome.htmlFrom the Missouri Botanic GardenNote that these are only to order, but we focus on the familyMostly based on APG
A.P.G. • Angiosperm Phylogeny Group • Group of scientists that wanted to standardize the previous groupings • Based on molecular data – monophyletic groups • See chapter 6 for more info • Two seminal papers resulted • APG or APG I • APG II
APG II • Published in 2003 • Made clarifications from the 1998 paper • Basically just incorporated newer molecular data • Always changing and being revised, but with a good standard, that of the monophyletic group
An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IITHE ANGIOSPERM PHYLOGENY GROUP* A revised and updated classification for the families of the flowering plants is provided. Newly adopted orders include Austrobaileyales, Canellales, Gunnerales, Crossosomatales and Celastrales. Pertinent literature published since the first APG classification is included, such that many additional families are now placed in the phylogenetic scheme. Among these are Hydnoraceae (Piperales), Nartheciaceae (Dioscoreales), Corsiaceae (Liliales), Triuridaceae (Pandanales), Hanguanaceae (Commelinales), Bromeliacae, Mayacaceae and Rapateaceae (all Poales),
Why focus on the family? • Over 400,000 plant species • Only about 400 plant families • Many families are already monophyletic
Synoptic key • These keys define major characteristics of a taxon • Page 128-129 in your book • Useful to help in your discovery of plant families • Let’s try it out!
Using a Synoptic Key • Keys are great, but if you can recognize a family, you can go a lot quicker • None of you need a key to recognize a conifer now (at least I hope not) • We will focus on knowing families
Tips for learning families • Practice keying plants to family • Practice keying plants to genus • Consult books and the internet • Prepare a set of one-character/family tables • Make a family/character table • Flash cards • Study with friends