May 16, 2018

Buffalo Burr (Solanum rostratum) and its cousins

There are described my experiences with growing of 3 spiny Nightshade species which belongs to subgenus Leptostemonum and sections Androceras (Solanum rostratum and Solanum citrullifolium) and closely related sect. Crinitum/Sisymbriifolium (Solanum sisymbriifolium). They all are very ornamental and the last species creates edible fruits. They are closely related to numerous cultivated Solanum species as: potato, eggplant and tomato. They all have similar requirements and like sunny position but there are differences in the propagation ways of each one. 
Buffallo Burr (Solanum rostratum) in flowers
Solanum rostratum (syn. S. cornutum) (Buffalo-bur, Spiny Nightshade, Colorado Bur, Kansas Thistle, Mexican Thistle, Texas thistle) it is very ornamental medium size (about 0,3-0,6m = 1-2ft tall) annual herb with numerous bright golden-yellow flowers and blackish inedible berries completely covered by spiny calyx. It has different types of stamens in flowers (heteranthery). It is native almost to whole USA, part of Mexico and is introduced to Canada. This plant has also spread to Eurasia, Australia, and South Africa, where it is regarded as a troublesome weed. It likes well drained soils and much of sunlight. It is not very easy to propagation. Seeds need to be cold stratified by a few months or sown in autumn in cool cellar (or eventually outside). They germinates only in a dark so they should be sown about 1-1,5cm (0,4-0,6inch) deep. 
Plant with fruits (completely covered by spiny calyxes)
Solanum citrullifolium (Watermelon Nightshade) this is very similar species, but with violet-blue flowers. It is native to Southern USA (Texas, Oklahoma, Kansas, Iowa, Massachusetts, Delaware and Florida) and Mexico. It has the leaves similar in shape to watermelon, but prickly. The flowers are also heterantherous, with two-sided symmetry (as previous species). Its seeds germinates without any pre-treatment and do not need darkness (can be sown surface).
This species has leaves similar in shape to watermelon
... and violet flowers
The fruits also cover spiny calyxes

Solanum sisymbriifolium (Litchi Tomato, Sticky Nightshade, Red buffalo-bur, Vila-vila, Fire-and-ice plant, Morelle de Balbis) this is similar to previous ones prickly annual herb, but larger (to about 1,5-1,8m = 5-6ft tall) and with flowers (white or lavender, often changing a color with their age) with almost radiant symmetry. It is native to South America (Brazil, Argentina, Paraguay, Uruguay, Bolivia, Peru) and naturalized in Australia and South Africa. It has been planted in European botanical gardens as a curiosity since the 18th century and has been used as a trap crop in the UK to control potato cyst nematode (pest of cultivated potatoes). In modern times it is more and more often planted as rare garden fruit plant (in several named varieties). The red fruits (covered, but not completely, by spiny calyxes) are edible but without very distinct aroma, sweetish-acid (something similar in taste to wild plums). This is usually easy to propagation, but some forms need short chilling period to germinating (about 3-4 weeks of cold stratification). They should be sown shallowly or surface (do not need darkness to germination).
This species has whitish flowers
... and leves similar to London Rocket (Sisymbrium)
This is relative to potato and as potato is attacked by Colorado beetle
The fruits are not completely covered by spiny calyxes
Ripening fruits
Mature red fruits are edible (tastes similar to wild plums)

No comments:

Post a Comment

Exotic Nettles (Urtica spp.) - part 2

I have already described some nettle species on March 2018. Now I am writing about my experiences with growing 3 new species + a few a...