The Definition of a Subshrub

What They Are and Why They Are Important

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You may have heard the word "subshrub" used to identify certain plants. Just what are subshrubs though?

One way to classify plants is whether they have soft herbaceous growth or hard woody growth. Subshrubs are unique in that they have characteristics of both herbaceous and woody plants. Their base is woody, while they produce new herbaceous growth during the primary growing season. Many herbs fall into this category.

Subshrub or Shrub

A Subshrub is technically called a chamaephyte, It is a shrub that bears hibernating buds on persistent shoots near the ground, usually woody shrubs with perennating buds borne close to the ground, no more than 25 centimeters (9.8 in) above soil surface. One significance of the closeness to the ground is that the buds remain within the surface boundary layer and are thus somewhat protected from harsh winters. Prostrate shrub is a related term. "Subshrub" is often used interchangeably with "bush". Another name for this type of plant is semi-shrub.

Chamaephytes are especially important in stressful environments, for example in alpine, arctic or dry ecosystems, often grazed by herbivores, and on nutrient poor soils or rock.

Because the criteria are matters of degree rather than of kind, the definition of a subshrub is not sharply distinguishable from that of a shrub; examples of reasons for describing plants as subshrubs include ground-hugging stems or low growth habit.

Subshrubs may be largely herbaceous, with overwintering perennial woody growth much lower-growing than deciduous summer growth. Some plants described as subshrubs are only weakly woody and some persist for only for a few years; others, however, such as Oldenburgia paradoxa live indefinitely, rooted in rocky cracks.

Subshrubs have abundant growth branching upwards from the base, with the upper stems dying back at the end of each growing season.

Small, low shrubs such as lavenderperiwinkle, and thyme, and many members of the family Ericaceae, such as cranberries and small species of Erica, are often classed as subshrubs. Subshrubs can also include cushion plants. A cushion plant is a compact, low growing, mat forming woody plant.

Other Examples of Subshrubs

Examples of subshrubs include:

  • Sunset Hyssop
  • English Lavender (Lavandula angustifolia)
  • Sage (Salvia officinalis)
  • Russian Sage (Perovskia atriplicifolia)
  • Deerwood (Lotus scoparius)
  • Wormwood (Artemisia absinthium)
  • American Feverfew
  • Babie's Slippers
  • Bastard Pimpernel
  • Beach Heather
  • Beggar's Lice
  • Bloodleaf
  • Blue Star
  • Sarsaparilla
  • Wild Sarsaparilla
  • Bur Marigold
  • Chrysanthemum frutescens 
  • Cleome pinnata 
  • Compass Plant 
  • Coral Gem
  • Desert Plum
  • French Honeysuckle
  • Dwarf Elder
  • Indian Beet
  • Horseshoe Vetch
  • Kiss-Me-Over-the-Garden-Gate
  • Life-of-man
  • Loosestrife 
  • Lotus Americanus
  • Lotus Berthelotii 
  • Lotus Corniculatus 
  • Marguerite 
  • Marguerite Daisy 
  • Marsh Rosemary 
  • Matchbush 
  • Matchweed 
  • Matilija Poppy 
  • Meadow Beauty 
  • Milkwort 
  • Mountain Avens 
  • Old-maid's Bonnet 
  • Pachysandra 
  • Paris Daisy
  • Periwinkle 
  • Petty Morel
  • Pinwheel 
  • Poverty Grass
  • Prairie Bird's-foot Trefoil
  • Prairie Dock
  • Prairie Lotus
  • Prairie Trefoil
  • Rocky Mountains Cherry
  • Sagebruch
  • Sea Lavender
  • Wormwood (Aeonium haworthii)