About

Asplenium platyneuron (syn. Asplenium ebeneum), commonly known as ebony spleenwort or brownstem spleenwort, is a fern native to North America east of the Rocky Mountains and to South Africa. It takes its common name from its dark, reddish-brown, glossy stipe and rachis (leaf stalk and midrib), which support a once-divided, pinnate leaf. The fertile fronds, which die off in the winter, are darker green and stand upright, while the sterile fronds are evergreen and lie flat on the ground. An auricle at the base of each pinna points towards the tip of the frond. The dimorphic fronds and alternate, rather than opposite, pinnae distinguish it from the similar black-stemmed spleenwort.

The species was first described in 1753 by Linnaeus as Acrostichum platyneuros, although Linnaeus' type drew on material from several other species as well.

How to grow it

The ebony spleenwort is sometimes grown as a terrarium or garden plant. It can be cultivated in sandy peat, subacid garden soil, other gravelly, sandy or gritty soils, or potting mix under moist to dry conditions. Both acid and alkaline soils are acceptable. Good drainage is essential, and the species will grow even in dry soil. Partial sun or low to high light is recommended, although full shade is tolerated. Plants are said to be easy to maintain once they have become established, but it has been described as "rather difficult" to grow in Germany. Conrad Loddiges found it necessary to use artificial heat to cultivate ebony spleenwort in Great Britain.

Where it grows

In North America, A. platyneuron is native throughout the eastern United States from southern Maine to the southeastern corner of Wisconsin, south to Florida and west to eastern Nebraska, Kansas, Oklahoma, and Texas, and in the far southeast of Canada. It is also found around the meeting point of Colorado, New Mexico, and Oklahoma, and in isolated small populations in New Mexico, Arizona and the West Indies. Outside of North America, A. platyneuron is found in tropical and subtropical southern Africa, a distribution not known for any other North American fern. It ranges from the Western Cape province of South Africa northwards along the eastern seaboard to Gauteng and Mpumalanga provinces, its distribution including Lesotho. An isolated population was found on serpentine soil in an oak woodland in Slovakia in 2009. Since the 1960s, A. platyneuron has spread rapidly and aggressively in the Great Lakes region, where it was formerly uncommon. Though widespread in southern Africa, it is not particularly abundant, and in that part of its range is most commonly found in Lesotho.

Other Asplenium plants

Black spleenwort · Asplenium aequibasis · Egyptian spleenwort · Asplenium anceps · Bird’s Nest Fern · Asplenium appendiculatum · Asplenium arcanum · Fern · Asplenium attenuatum · Eared Spleenwort · Bird's Nest Fern · Azorean Spleenwort