http://www.biovirtual.unal.edu.co/colecciones/datos/herbario/consultasHerbario.jsp#
When you click on link an extra window will appear listing the families that have been databased. Currently approximately 25% of the collections are online. To search there are 4 options - from left to right:
Search species by Genus/Species OR search specimens from a specific Collector OR search the Types.
If you have a species in Alaska, Brazilian Amazon, Cameroon, Canada, Central Africa, Congo, Indonesia, Russia or Venezuela, then this site might be useful:
http://www.globalforestwatch.org/english/interactive.maps/index.htm
The interactive maps are quite detailed with GIS layers relating to forests. Some of the data can be downloaded as well.
GBIF have recently added a pretty neat tool to their data portal. You now have the opportunity to create a niche model based on the occurrence data from GBIF. Niche models attempt to define areas of suitable habitat for a species.
Simply search for a species and in the Actions window click the option for 'create niche model'.
A match made in heaven?
GBIF occurrence data and Google Earth: http://ge.gbif.net/
Aside from searching gbif and displaying occurrence records in google earth (something already avaialble via the main gbif portal) there are a couple of extra tools.
You can link directly to the Alexandria gazetteer via a nice query interface and it will create a placemark for your search results:.
Many of you seem to have found this site already, but just in case you haven't:
http://www.herbarium.reading.ac.uk/index.php
This is great for:
Phanerogams: Europe, especially Great Britain and Ireland, the Iberian Peninsula, North Africa (especially Morocco), Macaronesia, the Middle East, cool temperate South America; Pteridophytes: worldwide; Bryophytes: worldwide; Lichens: Europe, especially Great Britain and Ireland, Morocco.
Also there is a Mediterranean Plants Identification and Distribution Link.
Click on "Buscador" to add genus/species name. Then Buscar and then on the various symbols to see distribution maps, Legal status (E. legal - i.e. in IUCN, habitat directives), photos etc.
