Parasitic Plant Connection

Cynomoriaceae Lindl.

Family Description

Distribution Map
Cynomoriaceae Distribution Map

List of Genera

Cynomorium has two species, C. coccineum of northern Africa and the Mediterranean region and C. songaricum of western Asia. The latter species, known as "suo yang" in Chinese and is extensively used in herbal medicines. The genus is sometimes included within Balanophoraceae, but unlike that family it has bisexual flowers intermixed with male and female flowers within the dense inflorescence. Cynomorium has been known for thousands of years by ancient people who used it for food, medicine, and even for dyeing. Arabs call the plant "tarthuth" and Bedouins ate the interior portions of fresh young stems, prepared infusions of older stems to treat colic or stomach ulcers, or dried and pulverized the plant for use as a spice or condiment with meat dishes (see wonderful article by Robert Lebling HERE). Medicinal uses of tarthuth can be traced to Al-Kindi, Al-Razi (Rhazes), Ibn Masawayh, Ibn Wahshiya, and Maimonides but the plant became known to Europeans only in the 16th century. A group called the Knights Hospitaller of St. John operated a hospital in Jerusalem and learned of the medicinal qualities of tarthuth from local Muslim physicians. When the Crusaders lost Jerusalem to the Muslims, they moved to the island of Malta where Cynomorium was also native. The site where "Maltese Mushroom" grew (Fungus Rock) was thereafter vigorously guarded and thieves were imprisoned or made galley slaves. The "treasure of drugs," as the Arabs called it, was used for a variety of purposes, including treating apoplexy, venereal disease, high blood pressure, vomiting, irregular menstrual periods and as a contraceptive and toothpaste. In his book "The Private Life of Plants, David Attenborough implies that the medicinal qualities of Cynomorium can be attributed to the "Doctrine of Signatures," i.e. that if a plant bore a physical resemblance to a part of the human body, this plant was useful in treating a disease associated with that part. For example, because Cynomorium appears reddish-brown and darkens upon drying, it could be considered useful in treating ailments of the blood. Moreover, the phallic shape meant the plant could also be used to treat sexual problems. Evidence is now accumulating that the ancient Muslims may have been correct with regard to the medicinal qualities of tarthuth. See References (below) for modern pharmacological work aimed at determining actual biochemical activity.

Photographs

Cynomorium coccineum

Cynomorium songaricum

Phylogeny

This family, containing only the genus Cynomorium, was treated as a member of Balanophoraceae in Kuijt (1969). The concept that the two families were separate is not new. In fact, Takhtajan’s 1987 classification placed Balanophoraceae in Magnoliidae and Cynomoriaceae in Rosidae.  Unfortunately in his 1997 classification he re-united them with Balanophoranae! Nickrent et al. (2005 BMC Evol. Biol. pdf HERE) showed that Cynomoriaceae was not closely related to Balanophoraceae but was a component of Saxifragales.

A large-scale study of angiosperms (561 taxa) by Jian et al. (2008 Syst. Bot.) questioned our result, indicating that Cynomorium belonged in Santalales.  These data are unpublished, nor was a voucher indicated.  But given the phylogenetic position, it is possible the authors accidentally used a sample of Balanophoraceae. It should also be pointed out that these authors erroneously indicated less than 50% bootstrap support for a Cynomorium / Saxifragales relationship in Nickrent et al. (2005).  This is not accurate, for this relationship had 98/100 (MP/Bayesian) support. Also, Nickrent et al. (2005) included Santalales and Balanophoraceae in their analyses, thus Cynomorium had “the opportunity” to group with these taxa, but it did not. Thus, at this time it does not appear that sufficient data exist to consider seriously this alternate result.

But the confusion doesn’t stop there!  In 2009 Zhang et al. (Journal of Systematics and Evolution, published in China) conducted a phylogenetic study using the chloroplast inverted repeat.  They showed that Cynomorium songaricum was sister to Rosaceae (Prunus and Fragaria) with 99% BS support. 

The evidence supporting (and not supporting) the phylogenetic placement of Cynomoriaceae among angiosperms was discussed in a Supplement to Su et al. (2015) HERE. More recently, the position of this family within Saxifragales has been confirmed in Bellot et al. (2016. Assembled plastid and mitochondrial genomes, as well as nuclear genes, place the parasite family Cynomoriaceae in the Saxifragales. Genome Biology and Evolution 8:2214–2230).

But it seems that some authors insist on "beating a dead horse", making false statements about previous phylogenetic work, and ignoring overwhelming evidence. The very recent book by Soltis et al. (2018, Phylogeny and evolution of the angiosperms, The University of Chicago Press) on p. 195 said "Some analysis [sic] placed Cynomorium coccineum (Cynomoriaceae) in Saxifragales (Nickrent et al. 2005), albeit with low support."  The erroneous Santalales and Rosales positions are also repeated here (why is this necessary?) and the 2016 work from the Renner lab is not cited. The closing statement "Obviously, more study of Cynomoriaceae is required" may be true in terms of various fascinating molecular evolutionary questions, but it is certainly not true in terms of phylogenetic placement!



References


Last updated: 15-Nov-20 / dln