Thursday, 29 January 2015

MELBOURNE STREET TREES 101 - CEREUS

I am stretching the definition of "tree" by inlcuding this "succulent shrub" under its umbrella, but one cannot but be impressed by the sheer size and majestic presentation of this giant cactus. Cereus is a genus of cacti (family Cactaceae) including around 33 species of large columnar cacti from South America. The name is derived from Greek (κηρός) and Latin words meaning "wax" or "torch". The genus Cereus was one of the first cactus genera to be described; the circumscription varies depending on the authority. The term "cereus" is also sometimes used for a ceroid cactus, any cactus with a very elongated body, including columnar growth cacti and epiphytic cacti.

Cereus are shrubby or treelike, often attaining great heights (C. hexagonus, C. lamprospermus, C. trigonodendron up to 15 m). Most stems are angled or distinctly ribbed, ribs 3–14, usually well developed and have large areoles, usually bearing spines. Cephalium is not present, Cereus mortensenii develops pseudocephalium. Flowers are large, funnelform, 9–30 cm long, usually white, sometimes pink, purple, rarely cream, yellow, greenish, and open at night. Fruits are globose to ovoid to oblong, 3–13 cm long, fleshy, naked, usually red but sometimes yellow, pulp white, pink or red. Seeds large, curved ovoid, glossy black.

The specimen illustrated here is Cereus paraguyanus, and all but the last photo are from Melbourne's Botanic Garden. The last photo is from my neighbourhood in inner suburban Melbourne, just to prove how well suited our climate is to the growth of this cactus in Melbourne. In out back garden we have two of these cacti growing in large pots, one about 1.6 m tall, but not yet flowering. I have seen another three large flowering specimens in our immediate vicinity.

This post is part of the Floral Friday Fotos meme.








3 comments:

  1. wohoa! cactus flowers! never seen before!

    xoxo, Juliana | PJ’ Happies :) | PJ’ Ecoproject

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  2. That is a very unusual plant. Great pictures, pretty flower.

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