Stealth Passifloraceae: Piriqueta versus Turnera

With five-petalled, often yellow flowers, Turnera and Piriqueta can easily be mistaken for members of the Malvaceae (like Sida). A closer look at a flower shows a three-part ovary and three styles. The floral formula 5-5-5-3 (5 sepals, petals, and stamens and 3 carpels) is unusual. (Part numbers usually match or are at least multiples of each other. Our Sida flower would have 5-5-lots-5 or 10).
This observation of Turnera sidoides shows the un-Sida-like flower with its unusual combination of 5 stamens and 3 stigmas .

A cross-section of a fruit (which matures to a three-segmented capsule) would show parietal placentation (placentas on the wall of the fruit rather than at its center). This is also an unusual trait.
The unusual features of Piriqueta and Turnera are typical for the passion flower family, which is where these taxa are now placed.

Turnera and Piriqueta both have pinnately-veined leaves, whereas similar-looking Malvaceae usually have at least slightly palmately-veined leaves (so perhaps 3-5 main veins joining at the base of the leaf).

Now for the tricky part: How do you tell these apart?

Unfortunately, there's no really easy way, particularly if you're working from a photo or two. There are differences in hair types on the foliage (Gonzalez & Arbo 2004), but also a good deal of overlap, and you need a microscope or serious closeups to see them. Turnera can have "stellate" trichomes, which range from a pair of branches joined at the base to clusters of up to eight rays. Piriqueta has porrect-stellate trichomes, with a cluster of rays at the base and a central point projecting up and out of the cluster (Gonzalez & Arbo 2004). Good luck with that.

Here are some key differences taken from Zelenski & Louzada (2019). Their paper on the Brazilian species of these genera has nice keys, thorough descriptions, and lovely line drawings -- well worth checking out.

Piriqueta leaves lack nectaries (sugar-secreting glands for bribes to ants). The flowers have inconspicuous to no bractioles (slender green projections at the base of the calyx). The 46 species of the genus are neotropical, with species native throughout the Americas (North, Central, South).
This observation of Piriqueta in flower shows the 5 stamens and 3 stigma feature, as well three-carpellate fruit and flower buds without bracteoles around them .

Turnera leaves often have nectaries (sugar-secreting glands for bribes to ants) along the petioles.
For example, Turnera subulata with extrafloral nectaries at the base of its leaf.
This observation of Turnera ulmifolia shows the extrafloral nectaries at the base the leaves, and also its three-carpellate fruit.
Finally, Turnera flowers have conspicuous bractioles (slender green projections at the base of the calyx). The 143 species of the genus are split between the neotropics and Africa.
This observation of Turnera diffusa shows extrafloral nectaries along the teeth of the leaf blade, and a bracteole on the side view of the flower.

Works Cited:

A. M. Gonzalez, M. M. Arbo, Trichome complement of Turnera and Piriqueta (Turneraceae), Botanical Journal of the Linnean Society, Volume 144, Issue 1, January 2004, Pages 85–97,

Zelenski, A. and Louzada, R., 2019. The genera Turnera and Piriqueta (Passifloraceae sensu lato) in the state of Pernambuco, Brazil. Rodriguésia, 70. At

Posted on 15 April, 2023 19:10 by m_whitson m_whitson


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