One very valuable source of plants is in private seed lists. Both the Alpine Garden Society and the Scottish Rock Garden club produce seed lists every year. They are only available to members but there is a generous allocation of seeds for everybody. At this time of year people from many parts of the world will be collecting seeds to send to the various seed exchanges. Much of this will be garden seeds but also many people collect seed both from their own countries and places they travel to in the wild to add to the lists. Members who send seeds in do have an advantage but all members are entitled to a share. The Meconopsis Group based at the Edinburgh Botanical Gardens produce a seed list which of course contains a great range of Meconopsis seeds and these days other genera too. As you might imagine there is a huge amount of work involved in first rapidly producing a seed list to send out, then to collect in all the donations and sort them and then to packet up hundreds of seed numbers in thousands of packets and finally to send the seed out usually before Christmas while the seed

is still really fresh. All this is done by volunteers. Most Botanic Gardens also produce a seed list but usually this is only exchanged with other Botanic Gardens but they will sometimes provide seeds for very serious amateurs. There are also intrepid travelers who go out into the wild and collect seeds, I show the catalogue of  Holubec from Czechoslovakia from whom I have had some wonderful seeds. There are a number of collectors of native American seeds who issue annual catalogues. Commercial from proprietory seed companies will almost certainly be a year older by the time you buy it. 

Image - various stages of collecting and drying. Clay saucers dry seed well. Fleshy seeds like the Podophyllum shown need scooping out, perhaps washing to remove slime etc. and then drying (dried seed in petri dish). Top Right are this years cleaned and packaged seed ready to send off. Top Left - seed heads of an American species of delphinium drying. UNLESS you are disabled the seed exchange managers do expect seed to be clean and correctly labelled. YOU will find however that not everyone identifies what they send in correctly!