Thursday, May 21, 2009

Yellow flowered Mamms

This dainty cactus rewards the grower with showy and lemon-scented yellow flowers. Mammillaria surculosa is reported from the Mexican states of Tamaulipas and San Luis Potosi. In the wild it forms dense mats.

In cultivation it quickly clusters in a few years. The flowers are very individual for this genus with crocus-like petals.

This and the following plant were previously placed in the genus Dolichothele due to the large tubercles and relatively large flowers. Dolicothele has been relegated to Subgenus under Mammillaria.

Mammillaria baumii is another sweetly-scented yellow-flowered charming plant. In habitat it is often found in the shade mostly on bare rocks.

It comes from the Mexican State of Tamaulipas. I have seen this species near the town of San Vicente where it forms sizable low mats.

Wednesday, May 6, 2009

Ortegocactus macdougallii

This interesting cactus is only found in one small area, on Cero Cantaro, at San Jose Lechuguiri, Oaxaca.

The plant is named after Francesco Ortega who first brought the plant to the famous botanist Tom MacDougall and subsequently named by Alexander in 1961.

There has been attempts to refer this plant to the Genus Coryphantha but due to its isolation it must have evolved from an early ancestor which branched into Coryphantha and Ortegocactus. Philogenetic studies conducted in 2002 places this cactus between Coryphantha and the genus Neolloydia.

I have seen this plant half buried in scree in its habitat. The area is quite inaccessible. I have had to take several lifts which took me half a day to arrive. It grows on limestone rocks. Habitat cacti can develop the same red marking as their counterparts in cultivation.

The plant is small but will eventually clump. Plants in cultivation are usually grafted but I have grown these plants on their own roots without any problem.

Top picture shows a plant in cultivation.

Middle picture shows the habitat of Ortegocactus.

Bottom picture shows a clump of Ortegocactus macdougallii in habitat. The ruler is 15cm long (6inches)