Walleria gracilis, winter growing beauty

This is a hard plant to photograph, as it is quite delicate and this one was blooming under lights, where it weaves in and out among the pelargoniums and other South African geophytes that share the same winter home.  I grew it from seeds from Silverhill that took quite a long time to germinate.  I remember thinking it was summer growing, since it looks kind of like a mini gloriosa lily in growth, but it is in fact a winter grower, as would be expected when one realizes it comes from the Vanrhynsdorp area of the Cape.  Sprouts appear in fall and the wiry stems rise,with soft prickles on the leaf midrib undersides, and the bright white flowers marked with an inner blue ring appear sometime afterwards.  I have not been able to set seed on the plant that bloomed this year, its first, but there appear to be others in the pot that I can try crossing it with next year.  I am guessing that it is not self fertile.  Sometime in spring the plants will die down in the manner of other winter growing Cape geophytes.  Then it will be allowed to dry out and set aside along with many others that follow the same cycle until September rolls around.  At that time, my indoor garden, which keeps me sane during NY winters, will rise again from these summer sleeping pots. 

Cleome hirta, an African cleome

I got seed of this a few years ago from JL Hudson, and it is one of my favorite annuals.  It is hard to photograph because it is an airy plant, not dense and showy in the typical sense of many garden flowers.  It grows fast in warm weather, and sets copious amounts of seed in long thin pods.  Unlike the common garden cleome, it is not annoyingly prickly stemmed.  I like the unusual yellow markings which contrast nicely with the light purple base flower color.  The flowers are great favorites of bumblebees, and C. hirta will flower for a long period of time from mid/late summer till frost. For earlier flowering in northern parts of the US, it is best to start it early indoors, as is the case with Ceratotheca triloba, another African annual worth growing. 
There are several other species of Cleome in southern Africa, but I have yet to have success in germinating the yellow flowered ones.  I assume they have some kind of inhibitor present in the seed, or they may require special treatment such as scarification.  I will keep trying to get them to germinate, as the yellow flowered African species can be quite spectacular in flower.

Pycnostachys dawei, a tale of storage and survival

I grew this east African species many years ago at the New York Botanical Garden from a plant I got from Logees.  I noted that even then the plant seemed to be afflicted by virus, but I was able to get seed set with effort, and eventually I refrigerated that small sample of seed.  Years later, Susannah Strazzera of Wave Hill, a wonderful little garden tucked away in the Riverdale area of the Bronx, told me about how hard it was getting to get this species to bloom in recent years.  I looked at the plants, which came from the same source and had been cutting propagated over many years, and it was apparent that they were afflicted even worse with virus symptoms--leaves were narrow, twisted, color uneven, growth abnormal--no wonder the poor things were but a shadow of their former glory.  So I went and resurrected my seed stash, now over 15 years old, and got a few seeds to germinate, maybe 20% if that--not surprising since I did not refrigerate the seed immediately upon harvest, in fact I am not sure how long it was stored at room temp before I got it into the fridge, but it was probably not more than a couple of years--plus it was in the fridge for well over a decade.  I brought some healthy young plants (many viruses are not seed borne and these can be cleared from infected stock by growing a new generation from seed) back to Susannah, and she propagated them and grew out the magnificent flowering specimens shown above, which were just beginning their wonderful winter show when I visited the Wave Hill conservatory around Christmas.  She will try and save seed for me to replenish my seed bank later on. 
I don't think Logees carries this species any more, and I have not come across it in cultivation in the US in many years, though I suppose it could exist in some California or Florida garden/nursery.  It is evidently still in cultivation in glasshouses in the UK, and perhaps other European nations.  It would be difficult, if not impossible with current nightmarish bureaucratic craziness to get more stock from Africa.  This is due in large part to the Convention on Biodiversity, a well meant but seriously flawed attempt to conserve the world's biodiversity.  This treaty will basically doom many plants  to extinction by making their export to other nations legally very difficult or impossible, so they will die when global climate change and habitat destruction take them out in their native ranges.  Add to this the increasing difficulty and ever more restrictive regulations coming down the pike for importing plants into the USA, and it becomes easy to see why serious horticulturalists need to make better use of their refrigerators as seed banks.  In my experience, seeds of many sorts can be stored in simple paper envelopes (I use either coin or stamp envelopes) in the refrigerator for over a decade, perhaps much longer (haven't had many more than 15 years).  I understand that seeds can also be frozen, but I worry about the kind of damage (freezer burn) that appears on frozen food that has been stored too long, though I imagine that storing them in sealed containers with desiccant might help. Plus I don't have to worry about potential damage from thawing every time I open the door or a power outage occurs, and I am not concerned with storing them centuries beyond my lifetime, after all I won't be worrying about it then!  I do wish I had realized the benefits of cold storage of seeds before, as there are a few pelargonium species I had during my research days at Cornell that I set seed on, but that I lost when the seed got too old to regenerate after a few years at room temperature. 
Another nice aspect of storing seeds is that one can grow several kinds of unusual/commercially scarce or  unavailable annuals in a limited area by skipping years, simply save the seed one year, stash it in the fridge, and grow something else in its place for a few years, then start some stored seeds of that annual again a few years later.  It also is a means of conservation on a very basic level, which is something worthwhile in my view, despite all the imperfections.  True, a botanical garden or government administered seed bank with wild collected samples is best, but that won't happen to the necessary degree it needs to happen.  Academic criticisms such as the use of garden seed that is not documented wild source, possible hybridization, and inadvertent selection for garden conditions have a degree of validity, but IMHO conservation scientists obsess over these details too much while the forests and savannas of the world burn faster and climate change accelerates more quickly they are capable of responding to in any meaningful fashion.  So lets do our part, however small, to conserve at least a few species and unusual selections of the wonderful flora our planet bequeathed us with, so that future gardeners might have a chance to enjoy some of the flowers that thrilled us in our lifetimes and that might not otherwise have continued their existence without our help.