Everyone knows at least one sansevieria, the "mother-in-law tongue," S. trifasciata var. laurentii. Go into any office building that hasn't been renovated in the last 20 years, and you'll be sure to find a few, tucked away in dark corners, watered once a year, but still clinging to life.
Most of the 70 or so sansevierias are lesser variations on that theme, but there is one that's quite interesting, S. cylindrica.
Growth Habit: Upright, with two to six cylindrical stems per shoot, up to 1.5m (5 feet) tall. This is the only sansevieria that has leaves that are round in cross section, rather than flattened.
Scientific name: Sansevieria cylindrica Bojer.
Common names: Bowstring Hemp, African Spear, Spear Sansevieria.
Etymology: The generic name comes from Raimondo di Sangro, prince of San Severo, Italy, in the 1700's. The specific name you can probably guess .
Taxonomy: Described by Bojer in 1837. Britton described two varieties, S. c. var. cylindrica and S. c. var. patula, in 1915 (see Notes).
Distribution: South Africa.
Cultivation: Easy in average succulent soil. This species seems to be quite thirsty, and doesn't like drying out for long in the summer. It's easy to tell when it wants more water, because the leaf tips will start to dry up. Mine (in a 7" clay pot) gets watered weekly during the summer, and every three to four weeks during the winter.
Like most sansevierias, this species spreads by stolons (underground stems) and would thus prefer a lot of room. If the growing point of a stolon bumps its head against an obstacle, for example the wall of a pot, it may continue trying to grow, with the result that the rest of the stolon gets pushed out of the soil.
Minimum temperature: Probably hardy to close to freezing, but I keep it at 55 degrees minimum.
Conservation Status: Not protected. Common in cultivation.
Notes: According to Jacobsen, S. c. var. cylindrica has two to four leaves per shoot, whereas S. c. var. patula has three to six, and the leaves of S. c. var. patula are more recurved than the type.
In the last year or so, this species has become the new Lucky Bamboo. According to some sites, it removes toxins from the air. One site says, "For centuries they were grown because they are believed to share the same eight virtues as Taoist deities, the Eight Immortals." Another site markets it under the name "Wisdom Horns," with the tag line, "In earlier times the horns were thought to capture wisdom. As your own wisdom expands, more horns grow."
Thanks to firstname.lastname@example.org for that last pic.