Although all spiders are venomous there aren’t that many that are potentially harmful to humans and in my part of the world there are only three or four: the brown button and black button spider, the (‘dreaded’) violin spider – In the South African National Collection of Arachnida, which houses more than 140 000 spider specimens collected over a 40-year period, only 120 specimens (0.08% of the collection are violin spiders. Of these 120 specimens, only 11 were collected inside buildings.) – and this one:
The long- legged sac spider Cheiracanthium sp. Family Eutichuridae.
This is what Astri Leroy has to say about this spider in the booklet Venomous Spiders in South Africa
Long-legged Sac Spiders are medium-sized, ( body length approx. 10 mm) common and widespread and found in most habitats. They are nocturnal hunters and rest by day in temporary sac-like silken retreats in vegetation. They often come indoors and will make their retreats in folds of fabric and other hiding places. Their fang base are black, the fangs large for their size and because they often come into close contact with people they account for about 75% of known spider bites in South Africa. Their venom is cytotoxic (cell destroying) and bites cause small necrotic wounds which take several weeks to heal completely. Treatment is symptomatic and medical attention does not need to be sought. The bite site should just be kept dry and clean and it will heal on its own.
And here is what one looks like. This is a female. Photographed hiding among the petals of a rose in the garden last week.