Pencil Bush. Euphorbia tirucalli, Spurge Family ( Euphorbiaceae ), Pencil Bush. Also Called: Pencil Cactus, Milk Bush, Firestick Plants, Pencil Cactus, Sticks on Fire, Indian Tree Spurge, Naked Lady, Pencil Tree, Pencil Euphorbia, Rubber Hedge Euphorbia, Aveloz, saptala, satala, sher-kandvel, Euphorbia rhipsaloides, & Euphorbia viminalis. We wish to thank Wikipedia, the free encyclopedia for some of the information on this page. We share images and information with Wikipedia. Euphorbia tirucalli is indigenous to tropical northeastern, central and southern Africa. It grows naturally on some surrounding islands, and the Arabian peninsula. It has been introduced to many other tropical regions. They are salt resistant, & grow well in coastal regions. E. tirucalli produces a poisonous, milky latex. It is extremely irritating to the skin and mucosa. Contact with the skin causes severe irritation, redness, and a burning sensation; contact with the eyes may cause severe pain, and in some cases temporary blindness for several days. It has been used for cancer, excrescence, tumors, and warts in many cultures. But, all scientific studies say to avoid any contact with this latex. It is poisonous !! Pencil tree grows with single or multiple trunks which support light green, pencil thick, succulent branches. Pencil tree can reach a height of 20 - 30 feet with a 6 - 10 feet spread. The main trunk and branches are woody and brown, but the younger branches are green and cylindrical, looking like pencils. The leaves are very small & they are shed early. What is usually called the flower is really a group of petal-like bracts (modified leaves). The true flowers, which are centered within the bracts, are white to light purple, with yellow anthers. They are inconspicuous. In tropical and subtropical climates, pencil tree is used as a specimen, or background plant, and also in mixed hedges. It can be used as a patio plant, in a container. Quick Notes: Height: Height about 30 - 30 feet. Spreading about 6 - 10 feet. In cultivation they are usually smaller. Flowers: Inconspicuous true flowers, which are centered within the bracts. Flowering Time: Late Winter/Early Spring; Late Summer/Early Fall. Leaves: Evergreen, usually green, blue-green and fleshy. Found: Tropical northeastern, central, and southern Africa. Hardiness: USDA Zone 9a: to -6.6 �C (20 �F) USDA Zone 9b: to -3.8 �C (25 �F) USDA Zone 10a: to -1.1 �C (30 �F) USDA Zone 10b: to 1.7 �C (35 �F) USDA Zone 11: above 4.5 �C (40 �F) Soil pH requirements: 6.1 to 6.5 (mildly acidic) 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline) 7.9 to 8.5 (alkaline) Sun Exposure: Full Sun. Elevation: 0 to 2,900 feet In Arizona. In its native habitats, it is usually between 0 to 2,300 feet. Habitat: Well-drained, sandy, poor to moderately fertile soils. A Xeriscape Landscape plant. Miscellaneous: An ideal xeriscape landscape plant at low elevations in Arizona. It is poisonous !!