Welwitschia mirabilis - one of "most bizarre plants on earth."

Welwitschias are extraordinary plants and certainly rank among the top ten list of "most bizarre plants on earth." 

Welwitschia is a monotypic genus of gymnosperm plant, composed solely of the very distinct Welwitschia mirabilis. The plant, which is considered a living fossil is named after the Austrian botanist Friedrich Welwitsch who discovered it in 1859. The geographic distribution of Welwitschia mirabilis is limited to the Namib desert within Namibia and Angola.

Welwitschia grows from a short, thick, woody trunk, with only two leaves that continuously grow from their base, and a long, thick taproot. After germination, the cotyledons  grow to 25–35 mm in length, and are followed shortly afterward by the appearance of two permanent leaves.
These leaves are produced opposite of the cotyledons, and continue to grow throughout the entire life of the plant. They eventually grow to a length of 2–4 m and usually become split into several strap-shaped sections.  The species is dioecious, with separate male and female plants. Fertilization, that is, the transfer of the pollen from the male to the female strobili, is carried out by insects that are attracted by "nectar" produced on both male and female strobili

Watering: The plant absorbs water through structures on its leaves, harvesting moisture originating from dew that forms during the night.

Light: Welwitschia mirabilis needs full sun but it should be under roof when it rains.  So it will be great if Welwitschia mirabilis locates in the greenhouse.

Soil: normal soil for cactus and it should be well-drained.  If its leave becomes yellow, it means that you water too little.

Propagation: Welwitschia mirabilis is propagated from seed. Fresh seed will germinate in 45-60 days at 85°F (30°C).

Pelecyphora aselliformis

P. aselliformis is a well known medicinal peyote sold in the markets of San Luís Potosí, Mexico, and is used as a remedy for fevers and rheumatic pains. Extracts have also been shown to have antibiotic activity.  As this plan grows very slowly, therefore, it is usually grafted and rare.   So P. aselliformis may be a challenge for cactus collectors to grow it successfully.

Scientific Name: Pelecyphora aselliformis Ehrenberg
Family: Cactaceae 

Synonym: Mammillaria aselliformis, Anhalonium aselliforme, Ariocarpus aselliformis
Common name: Peyotillo, hatchet cactus, woodlouse cactus.

Origin: Mexico (San Luis Potosí - around the city of San Luis Potosí, above 6000 feet (1800 m))

Minimum Avg. Temperature: 50°F (10°C)

Sun Exposure: P. aselliformis needs a very well drained soil and requires strong sun to part sun to develop good spinal growth. You can grow this plant in the shade of bushes and don’t get direct sun at midday.  

Watering Needs: Watering should be rather infrequent, to keep the plant compact and not become excessively elongated and unnatural in appearance. Keep dry in winter, or when night temperatures remain below 10° C (but some people give this plant a light monthly watering to prevent the drying and shedding of the lower tubercles.) it is hardy to -4°C for a short period.  

Flowers: Pink to violet flowers with lighter outside petals, 2 - 3.5 cm in diameter. The floral buds are acuminate and appear on the apex. 

Blooming season: It normally flowers from February till October, but only if the sunlight is strong enough.

Propagation: It can be reproduced both by seeds and cuttings, but it is often grafted because difficult and slow to grow on its own roots. Older specimens shoot tillers from under tubercles, so they can be grafted, which is a much easier way of propagation than sowing. Young seedlings are tiny and they need several years to reach adult size, and require  close care.

Source:

http://www.desert-tropicals.com

http://www.cactus-art.biz/

http://www.entheology.org