Understanding the Grape Family: The Vitaceae
To understand what else is in the grape family, it's essential to recognize the family's formal name: Vitaceae. The name is derived from the genus Vitis, which includes the common grapevine (Vitis vinifera). Characterized by woody, climbing vines with distinctive tendrils that grow opposite the leaves, the Vitaceae are an ancient lineage, with fossils dating back over 66 million years. While the Vitis genus holds significant economic importance for producing grapes, wine, and raisins, other genera within the family are notable for their ornamental value and distinctive forms. The inclusion of the genus Leea within Vitaceae is a recent taxonomic change, adding a group of shrubs and small trees to this predominantly vining family.
The Genus Parthenocissus: Famous Creepers
One of the most recognizable genera within the grape family is Parthenocissus, which includes several popular ornamental vines. These plants are widely grown for their climbing ability and vibrant autumn foliage. The tendrils of Parthenocissus are particularly notable for their adhesive, disc-like tips that allow them to cling securely to walls and other surfaces.
- Virginia creeper (Parthenocissus quinquefolia): Known for its five-leaflet, palmately compound leaves, Virginia creeper is a fast-growing vine native to eastern and central North America. Its foliage turns a brilliant crimson or purple in the fall, making it a favorite for adding seasonal color to landscapes. The plant's dark purple berries are a food source for birds, though they are poisonous to mammals.
- Boston ivy (Parthenocissus tricuspidata): Native to eastern Asia, Boston ivy is another common ornamental climber. Its leaves are typically three-lobed and can create a dense, green covering on walls and buildings. Like Virginia creeper, its leaves turn shades of red and purple in autumn.
The Genus Cissus: Diverse Vines
The genus Cissus is one of the largest within the Vitaceae family, encompassing hundreds of species, many of which are found in tropical regions. Cissus species can vary significantly in appearance, from lush foliage plants to unique succulent varieties.
- Kangaroo vine (Cissus antarctica): A common houseplant known for its glossy, green leaves. It is a robust climber that thrives indoors.
- Treebine (Cissus rhombifolia): Often cultivated as a houseplant, this vine has textured, rhomboid-shaped leaflets and a graceful, cascading habit.
- Veld grape (Cissus quadrangularis): This succulent member of the family is known for its distinctive quadrangular stems and medicinal uses in traditional cultures.
Other Notable Genera
Besides the well-known Vitis, Parthenocissus, and Cissus, several other genera contribute to the diversity of the grape family:
- Ampelopsis: Includes species like porcelain berry (Ampelopsis glandulosa), known for its striking, multicolored berries.
- Ampelocissus: A genus primarily found in tropical and subtropical regions, often featuring impressive and robust vines.
- Tetrastigma: This genus is particularly famous for its association with the parasitic plant Rafflesia, which produces the largest flower in the world.
- Leea: As mentioned, this genus of shrubs and small trees was recently integrated into the Vitaceae family, adding a non-vining element.
Comparison of Prominent Grape Family Members
| Feature | Common Grape Vine (Vitis) | Virginia Creeper (Parthenocissus) | Kangaroo Vine (Cissus) | Veld Grape (Cissus quadrangularis) |
|---|---|---|---|---|
| Common Use | Fruit crop, wine production | Ornamental climber | Houseplant | Medicinal herb, succulent |
| Leaf Structure | Simple, lobed, palmate | Palmately compound, 5 leaflets | Compound, typically 3 leaflets | Simple, often lobed |
| Growth Habit | Woody, tendril-climbing vine | Aggressive tendril-climbing vine | Trailing or climbing vine | Fleshy, succulent stems |
| Tendrils | Woody, coiled, leaf-opposed | Branched, disc-tipped for adhesion | Simple, sometimes absent indoors | Present on succulent stems |
| Fruit (Berry) | Edible, fleshy (grapes) | Dark purple, poisonous to mammals | Inedible, hard | Inedible |
| Key Feature | Economically significant fruit | Stunning autumn foliage | Indoor adaptability | Distinctive quadrangular stems |
Ecological and Evolutionary Context
The Vitaceae family's success can be partly attributed to its leaf-opposed tendrils, a key adaptation that allows its members to efficiently climb and compete for sunlight. These tendrils represent a significant evolutionary innovation that has enabled the family to dominate various vegetation types, from tropical forests to temperate woodlands. While the economically important Vitis genus receives the most human attention, the wider family demonstrates incredible diversity. For example, the specialized interaction between the host genus Tetrastigma and its parasitic counterpart, Rafflesia, highlights unique co-evolutionary relationships within the group.
Separating Fact from Fiction
It is common to see grape family members, particularly Parthenocissus, confused with other climbing plants. For instance, Virginia creeper is often mistaken for poison ivy, especially since both are woody vines that can climb and display red fall color. However, Virginia creeper's distinctive five leaflets contrast sharply with poison ivy's three leaflets, a critical distinction for gardeners and hikers. Similarly, poison ivy is in a completely different family (Anacardiaceae), and its toxicity is caused by a different compound, urushiol, which is not present in Vitaceae species. The inedible or poisonous nature of berries from many Vitaceae species is another important characteristic that sets them apart from the edible grapes of the Vitis genus.
Conclusion
In conclusion, the answer to "what else is in the grape family?" is a rich and diverse collection of vines, shrubs, and succulents within the Vitaceae family. From the iconic Virginia creeper that colors North American autumns to the unusual succulent veld grape, these relatives of the common grapevine demonstrate a wide range of adaptations and uses. This family's defining features—such as leaf-opposed tendrils and succulent berries—are found across the genera, even as their appearances and ecological roles vary dramatically around the globe. While only the Vitis genus is cultivated for human consumption, the other members of the grape family hold significant importance in ornamental horticulture, traditional medicine, and botany, proving there is far more to this plant group than just the sweet fruit we know and love.
For further reading on the botanical classification and diversity of plant families, the Angiosperm Phylogeny Website offers an authoritative resource on the relationships within the Vitaceae family and all flowering plants (http://www.mobot.org/MOBOT/research/APweb/).
