Gymnocladus

This group contains 80 variable species. They are natives of South American countries from Argentina, north to Bolivia, Paraguay, Uruguay, and Brazil. The plants range from small stems, 11/2 inches across, to stems 8 inches wide and high. They range in color from blue-green to gray or brown. Most of the species flower profusely and at an early age. The long-lasting flowers range in color from white to light yellow and pink and only open fully in bright light. The blossoms are followed by plum-shaped fruits, which may be green, blue, or red. Commonly known as Spider Cacti and Chin Cacti, there is a chin-like protrusion right below each areole and spine cluster. G. baldianum is a solitary-growing cactus, which can reach its flowering size of 11/4 inches in 12 months from seed. This variety will eventually grow up to 31/2 inches across. Its flattened body is clothed in short, curved, light brown spines. In the spring it can bloom for several months. The flowers are 11/2 inches wide and colored white, pink, orange, red, or other in between shades. They are followed by green fruits. G. bruchii is a handsome variety that bears bell- or funnel-shaped, pale pink flowers. The small, flattened stems are ordinarily green, with straight or curved, white, bristly spines. This slow-growing plant will eventually form clusters up to 6 inches across. This plant loves sun or light shade. G. cardenasianum forms a solitary, grayish colored body that slowly grows up to 5 inches. It is densely covered with sometimes-twisted spines up to 21/2 inches long. Its pink flowers are produced sparingly in mid-summer. G. mihanovichii (Plaid Cactus) is an interesting plant that is a little more difficult to grow than the rest of the group. This species is variable, some having purplish bodies. This interesting species has also given rise to an occasional mutant seedling that lacks chlorophyll. Normally, these would die, since they cannot photosynthesize and produce food. However, some of these seedlings were grafted onto green stock plant and preserved. Since they contain the red pigment that would show as purple in a normal plant, these seedlings are bright red. They have been widely propagated and sold. G. mihanovichii variety 'Red Top' is commonly known as Ruby Ball and Hibotan. To keep it growing vigorously, it should be regrafted periodically. (There are also variants of this plant with pink pigments or yellow plants without the red pigment.) The Ruby Ball produces its pink flowers (although it's rare) in the summer. This plant cannot be left in the sun as its color may fade and tender body can burn.

Pot Cultivation

These plants need a minimum temperature of 41� to 48� F depending upon the variety. The Ruby Ball needs a minimum temperature of 50� to 61� F. In the wild, these cacti grow in the shade of other plants and leaving them in full sun may stunt their growth or scorch them. Grow them in rich, porous, sandy soil, which should be allowed to dry between waterings. Repot, in the spring, when their roots become crowded. Generally, they should be repotted every other year in order to renew their soil. However, this doesn't necessarily mean they'll need larger containers. Fill about a quarter of the pot with broken crocks, gravel, etc. to promote good drainage. Firm the potting soil. After repotting, do not water for a week or more.

Propagation

These plants may be increased by sowing seeds or removing offsets. Seeds may be sown in containers filled with a general-purpose cactus and succulent potting mix. Sprinkle the seeds evenly over the surface of the compost. Cover the seeds lightly with some grit, moisten the container and place in an area with high humidity and warmth. Transplant the seedlings when they are large enough to handle. Waiting too long until they are overcrowded can cause rot. Gently separate them so as not to damage the delicate roots. Transplanting will be easier if the soil is slightly moist. Seedlings can be potted singly or with several to a pot; however, they seem to do better together than by themselves.