Commelinaceae
(Dayflowers, Spiderworts)

Callisia fragrans (Lindley) Woodson 1942 (False Bromeliad)
This tolerant Mexican plant produces long flower stems with fragrant white to pale pink flowers arranged in clusters of three. The waxy leaves colour up in full sun with purple markings, especially leaf margins. In poor light the plant becomes flabby and elongated. Rosettes root easily to make new plants. Good for hanging baskets or ground cover in mild climates but will not tolerate significant frost. Various variegated cultivars may be seen. Widely cultivated for supposed cure-all properties, especially in Russia.
 
Photo: Larry Berg.

Callisia soconuscensis  Matuda 1954  Syn. C. guerrerensis Matuda 1967
A creeping Callisia whose stoloniferous stems form a large mat.
 
Native to Mexico and Guatemala.

Commelina erecta  Linnaeus 1753 (Erect or Slender or Whitemouth Dayflower)
growing about 3 miles South of Marathon, Texas, where it was fairly common on the road margins. This non-succulent plant has a tuberous root, perhaps explaining its tolerance of hot, dry conditions. It is widely distributed throughout the Americas and Africa.

Cyanotis somaliensis  C.B. Clarke 1895 (Pussy Ears)  Syn. Tradescantia somaliensis
A trailing plant with a succulent stem and markedly hairy, triangular leaves forming a basal sheath around the stem. The flowers in the leaf axils have blue petals with white marginal hairs. In some forms, the stoloniferous stem arises from a basal rosette.
 
Native to Somalia, Rwanda.

Dichorisandra thyrsiflora  J.C. Mikan 1820 (Brazillian Ginger)
The erect stems of this shrubby plant grow up to 5 - 6 ft tall with large sword-shaped leaves arranged around the stem. The inflorescence is a dense branching raceme of purple-blue flowers with yellow stamens and style. The foliage is killed by any degree of frost but may resprout from the rhyzomatous roots if these have not been damaged.
 
Native to tropical forests of Brazil and Peru and requires constant moisture and humidity.

Tradescantia micrantha   Torrey 1859   Syn: Callisia micrantha (Spiderwort)
This fleshy Tradescantia was growing in full sun on rocks in the baisin area within the Chisos Mountains of the Big Bend National Park, Texas. Where growing in full sunlight, leaf margins and stems were bright purple and the growth habit was compact, but on the shaded (South) side of the canyon plants had mainly green leaves and longer internodal stem segments.

Tradescantia pallida  D. Hunt 1975
Syn: Setcreasea pallida Rose 1911, S. purpurea Boom 1955

This scrambling perennial has long pointed purple-green leaves and small pink flowers with three petals.

Native to the Gulf coast of Mexico, but naturalised and invasive in Florida and Australia. As a houseplant, T. Pallida improves air quality by scavenging volatile organic compounds. Propagation from stem cuttings is easy. T. Pallida var purpurea is an especially-purple cultivar.

Tradescantia sillamontana  Matuda 1955 (Cobweb Spiderwort)
is a showy trailing plant with markedly hirsute leaves and a typical 3-petalled purple flower. It originates in the mountains of Northern Mexico so tolerates cool, frost-free winter conditions if kept on the dry side. Selected cultivars with pure white leaf hairs are available in the horticultural trade.

This erect shrubby plant has large sword-shaped dark green leaves with purple undersides. The small white three-petalled flowers are produced in boat-shaped purple bracts hidden in the leaf axils.
 
Tradescantia spathacea originates in the West Indies, Mexico, and Central America especially around Mayan sites, but has become naturalised in other warm climates. It is listed as an invasive species in Florida. This plant is commonly used in decorative displays or as a feature plant for a large pot. Cultivars with longitudinally-striped leaves are available.
 
Left: Tradescantia spathacea forma concolor. This form lacks the purple pigment in its leaves and bracts.

This scrambling perennial has pointed oval leaves, striped with purple-green and silver on their upper surface and with uniformly purple undersides. The small pink flowers have three petals.

Native to the Gulf coast of Mexico and naturalised in e.g. Florida. Cultivars of this plant are widely used as houseplants and are easily propagated by stem cuttings. In warm climates it is used as a dense ground cover but has the potential to become invasive. In Mexico it is used as a herbal tea. However, prolonged contact with the sap may cause skin irritation.