Thursday, May 16, 2019

[Botany • 2019] Zamia brasiliensis (Zamiaceae, Cycadales) • A New Species of Zamia from Mato Grosso and Rondônia, Brazil

Zamia brasiliensis  Calonje & Segalla

in Segalla & Calonje, 2019. 

Zamia brasiliensis Calonje & Segalla, a new subterranean-stemmed species of Zamia (Zamiaceae) from Mato Grosso and Rondônia, Brazil, is described and illustrated. It is compared to two morphologically similar species with adjacent geographic distributions: Z. boliviana from the Cerrado biome, and the Amazonian species Z. ulei. The new species shares unarmed petioles with Z. boliviana but is readily distinguishable by its much broader leaflets. Z. brasiliensis has leaflets somewhat resembling those of juvenile individuals of Z. ulei, but the latter species is easily differentiated by the presence of prickles on its petiole.

Keywords: Cerrado-Amazon Rainforest, Cycad, Endangered species, Endemic species, Gymnosperm, IUCN Red List

FIGURE 1. Vegetative characteristics of Zamia brasiliensis. A. Adult individual. B. Leaf, C. Middle leaflet. D. Cataphyll. E. Base of unarmed petiole.

FIGURE 2. Reproductive characteristics of Zamia brasiliensis.
 A. Abaxial side of microsporophyll. B. Adaxial side of microsporophyll. C. Cross section of pollen strobilus, abaxial side. D. Apex of pollen strobilus showing characteristic orange-brown tomentum E. Pollen strobili, near mature and immature, and new leaf showing inflexed ptyxis. F. Seed strobilus shortly after receptivity phase. G. Mature seed sclerotesta. H. Mature seed with sarcotesta. I. Mature seed strobilus, adaxial side. J. Distal half of mature seed strobilus. A–G based on material from Itaúba, Mato Grosso, H–J from Cacoal, Rondônia.

FIGURE 3. Zamia brasiliensis in habitat.
A. Submontane semideciduous forest habitat during the dry season (September 2018) at the type locality in Itaúba, Mato Grosso. Photographed with Rosane Segalla. B. Habit of plant at type locality. C. Woodland savanna (Cerradão) habitat in Cacoal (Rondônia) at the beginning of the rainy season (November 2018). Plants most common at boundaries of Cerradão and more open ‘campo cerrado’ habitats. D. Plant growing among grasses in woodland savanna.
Photo credits: A, C, D—Rosane Segalla; B—Márcio Cassiano de Jesus. 

Zamia brasiliensis Calonje & Segalla sp. nov.  

Diagnosis:— Zamia brasiliensis is distinguishable from Z. boliviana in having much broader leaflets and from Z. ulei in having unarmed petioles.

Etymology:— Zamia brasiliensis is the only species of Zamia endemic to Brazil. The specific epithet refers to its distribution which is restricted to this country.

Rosane Segalla and Michael Calonje. 2019. Zamia brasiliensis, A New Species of Zamia (Zamiaceae, Cycadales) from Mato Grosso and Rondônia, Brazil. Phytotaxa. 404(1); 1–11.

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