Viscum minimum

Viscum minimum
Viscum minimum leaf scales and flowers emerging from the host plant.
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Santalales
Family:	Santalaceae
Genus:	Viscum
Species:	V. minimum
Binomial name
Viscum minimum Harv.

Viscum minimum is a species of mistletoe in the family Santalaceae. It is a parasitic plant native to South Africa.

Description

In its native habitat Viscum minimum uses two species of succulents, Euphorbia polygona and Euphorbia horrida, as host plants. However, given the opportunity, the plant uses a range of succulents, including cacti, as hosts.

A mature Viscum minimum consists mostly of haustoria within the host plant, with small stems of less than one millimeter in length each with a single whorl of 2-3 scale-like leaves. A single flower, and later a red round fruit with a diameter of 8-9 millimeters, emerges from these stems. The leaves and stems are capable of photosynthesis, making the plant technically a hemiparasite.

The Viscum minimum mitochondrial genome has been sequenced, showing an unusual loss of genes or their functions.

Seed germination

• 
  Day 1: The sticky seed has landed on the host plant.
• 
  Day 4: Germination has commenced.
• 
  Day 10: The shoot emerges from the seed.
• 
  Day 23: The shoot has made contact with the host plant.
• 
  Day 30: The primary haustorium has developed.

Literature

• William Henry Harvey: Flora Capensis 2: 581
• Robert Allen Dyer: Two Rare Parasites on Succulent Species of Euphorbia, Euphorbia Review Vol. I (4): 29-32, 1935
• Thomas Goebel: Viscum minimum Harvey in der Sukkulentensammlung der Stadt Zürich, Kakteen und andere Sukkulenten 29 (1), 1978
• Frank K. Horwood: Two parasites of Euphorbia: Viscum minimum and Hydnora africana, The Euphorbia Journal, Vol 1: 45-48, 1983