Spinulum annotinum
interrupted clubmoss
Circumboreal (North America, Europe, Asia)
Deer Resistant
Native to North America
Overview
Spinulum annotinum is an evergreen, spore-bearing clubmoss of cool northern forests, spreading by long horizontal surface stems that root at intervals and send up stiff, erect leafy shoots 4-10 inches (10-25 cm) tall. The shoots are clothed in narrow, sharp-pointed leaves arranged in whorls, giving a bristly, bottlebrush look. Each season of growth is marked by a constriction along the stem, the interruption that gives the plant its common name. Cone-like strobili 0.4-1.5 inches (1-4 cm) long stand singly at the shoot tips in summer, releasing yellow spores. S. annotinum has no flowers or seeds and reproduces by spores and by vegetative spread of the creeping stems. It forms slow-growing colonies on acidic, humus-rich soil in coniferous and mixed woodland, often among mosses. The plant is circumboreal, ranging across northern North America, Europe, and Asia. It depends on cool, moist, shaded conditions and undisturbed ground, and recovers slowly once disturbed. Growth is gradual, with colonies expanding only a few inches a year.
Native Range
Spinulum annotinum is circumboreal, native across northern North America from Alaska and Canada south into the northern United States and the Appalachian mountains, as well as northern Europe and Asia. It grows in cool coniferous and mixed forests on acidic soil.Suggested Uses
S. annotinum is seen in native woodland and boreal plant study rather than in cultivation. It is occasionally part of cool, acidic woodland and bog-garden plantings where conditions match its native habitat. The creeping evergreen stems form a slow groundcover among mosses and conifers.How to Identify
Appearance
Size & Dimensions
Height4" - 10"
Width/Spread1' - 3'
Bloom Information
S. annotinum does not flower. It reproduces by spores released from cone-like strobili at the shoot tips. The strobili mature and shed yellow spores in late summer, roughly July to September.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight