A new species in the Lauraceae, Cinnamomum bladenense S.W. Brewer & G.L. Stott, is described from the Bladen Nature Reserve in southern Belize. The new species is similar to Cinnamomum brenesii (Standl.) Kosterm., from which it differs by its much smaller, narrowly-campanulate flowers, its inner tepals glabrous abaxially, its shorter petioles, its minutely sericeous younger twigs, and its abaxial leaf surfaces not glaucous and with prominent secondary venation. A description, preliminary conservation assessment, and photographs of the species as well as a key to and notes on the Cinnamomum of Belize are provided.

Cinnamomum , Lauraceae , Belize, Central America, Bladen Nature Reserve, Maya Mountains

Cinnamomum Schaeff. currently contains c. 350 species (Rohwer 1993), primarily in tropical Asia, with approximately 47 species found in the Neotropics (Lorea-Hernández 1996). We follow Lorea-Hernández’ (1996, 1997) use of leaf venation pattern, presence and distribution of domatia along midvein and secondary veins, pubescence type, inflorescence structure, pubescence of floral parts, hypanthium development and persistence of tepals in fruit as some principal features for distinguishing species in the genus. Lorea-Hernández’ revision of the genus for the Neotropics (1996) recognized only one species for Belize: Cinnamomum triplinerve (Ruiz & Pav.) Kosterm., a synonym of Cinnamomum montanum (Sw.) Bercht. & J. Presl (Rohwer 2014).

Floristic inventories in the Bladen Nature Reserve, Belize, Central America (Figure 1) from 2012–2014 resulted in the discovery of this species of Lauraceae. Fertile herbarium material collected from the type location was determined to be unique among any of the known species of Cinnamomum by comparing it with type and other herbarium specimens housed at MO, and online at F (http://fm1.fieldmuseum.org/vrrc/), HUH (http://kiki.huh.harvard.edu/databases/specimen_index.html), NY (http://sweetgum.nybg.org/science/vh/), US (http://collections.nmnh.si.edu/search/botany/), and JSTOR Global Plants (https://plants.jstor.org/). This plant is described here as a new species, and a key to and notes on the Cinnamomum of Belize are provided. Images of the holotype and at least one isotype will be available on The Missouri Botanical Garden’s electronic database TROPICOS (http://www.tropicos.org). Our examination of recent material of the genus in Belize confirms the presence of Cinnamomum areolatum (Lundell) Kosterm. for the country, as first reported by Standley and Steyermark (1946, as Phoebe areolata Lundell).

Figure 1. 

Elevation map of Belize with the type location (*) within the Bladen Nature Reserve.

Cinnamomum bladenense is unique for the genus in its relatively small flowers (< 2.3 mm from the base of the hypanthium to the apex of the tepals of dried specimens), and for its occurrence in the canopy of relatively tall-canopied (20–35 m) limestone slope forest. It has not been found on the adjacent apices of well-exposed ridges or on exposed rock outcrops, which are comparatively lower- and more open-canopied, much denser, of proportionately smaller-trees, and more unique floristically (Brewer et al. 2003). Limestone forests in the type location and nearby forests of similar vegetation have a high proportion of limestone specialists (Brewer unpubl. data), with soil properties significantly different than nearby soils on volcanic substrata (Winbourne et al. 2016). As far as we know, this new species appears to be unique among Neotropical species, perhaps along with C. salicifolium (Nees) Kosterm. from Mexico, by being associated exclusively with limestone. The latter species has abaxially pubescent tepals persistent in fruit, conspicuous and often dense and/or often spreading indument on the leaves and young twigs, villous filaments abaxially, and occurs in oak-pine forests.

In Lorea-Hernández’ (1996) revision of the Neotropical species of Cinnamomum Schaeff., specimens of Brewer & Stott 7529 key to C. brenesii, to which it is most similar (see diagnosis for differences), to C. paratriplinerve Lorea- Hernández (ined.), and, with considerable latitude in interpretation of indument, C. hartmannii (I.M. Johnst.) Kosterm. Cinnamomum brenesii is a Costa Rican and Panamanian species most often collected in disturbed and open habitats such as pastureland, roadsides and trail edges (vs. closed-canopy limestone hill forests). Cinnamomum paratriplinerve differs from the new species in having external tepals glabrous adaxially, entirely turbinate pedicels (at least some) in fruit, hypanthium glabrous inside, and generally conspicuously longer leaves. It also is a species of Costa Rica and Panama in disturbed areas (pastureland, secondary forest) as well as “natural”, closed-canopy forest. Cinnamomum hartmannii is a species of northwestern Mexico, in the contact zone between dry, oak temperate forests and semi-deciduous to deciduous tropical forests. It has glabrous filaments, and mainly pinnate leaves villous-tomentose beneath when young, among other differences. All other known Neotropical species differ in one or more significant character states, including persistent or entirely-deciduous tepals, domatia absent or secondary domatia present, domatia of pocket-like depressions below and ampullous above, and indument of spreading to erect hairs.

The three species of Cinnamomum in Belize – C. areolatum (Lundell) Kosterm. C. bladenense S.W. Brewer & G.L. Stott, sp. nov., and C. montanum (Sw.) Bercht. & J. Presl – are easily separated in the field without fertile material. In Belize, C. areolatum is typically a small tree (usually < 10 m, < 10 cm DBH), treelet or colonial treelets/shrubs, on the tops and shoulders of ridges on very acidic and nutrient-poor, igneous substrate in somewhat open and low woody vegetation (woodlands or natural disturbances in low forest), dominated by or with a significant component of Purdiaea belizensis (A.C. Sm. & Standl.) J.L. Thomas, occasionally with Cyrilla racemiflora L. and sedges such as Scleria P.J. Bergius and Rhynchospora Vahl, and/or associated with areas of fire-dependent ferns [e.g., Gleichenella pectinata (Willd.) Ching, Sticherus palmatus (W. Schaffn. ex E. Fourn.) Copel., Dicranopteris flexuosa (Schrad.) Underw.)], and never on alluvium. Its canopy is somewhat scattered along the stem, not confined to the upper portion of the stem, with leaves that are < 5 cm wide, coriaceous to thick coriaceous, the upper surfaces smooth and plane, and the veins inconspicuously impressed above. The leaves have conspicuous, densely-prominulous reticulum beneath, and domatia that are pocket-like below and ampullous above (at least some leaves) in the axils of the basal (or more) secondary veins. Cinnamomum montanum is found in ± closed canopy forest on rich alluvium or on acid substrata, never limestone, and is quite capable of exceeding 10 cm DBH and 20 m in height. It has the largest leaves of the three species, very often ≥ 5 cm wide, with at least some leaves > 10 cm long (often some much longer). It also has conspicuous ampullous and pocket-like domatia; however, its upper surface is not plane but “quilted” (coarsely bullate above, with long concave areas beneath) from the impressed midvein and secondary veins. Cinnamomum bladenense is found only on limestone slopes, has small leaves with short petioles, inconspicuous domatia not ampullous, and is a tree with a tight canopy at the top of the stem, even when small.

This species was discovered during the establishment of permanent sample plots in the Bladen Nature Reserve. Plots were demarcated and enumerated by a team from Ya’axché Conservation Trust (co-managers of the reserve) between 2012 and 2014, as part of ongoing biodiversity monitoring efforts. Funding was provided by the Protected Areas Conservation Trust (Belize), the Oleg Polunin Memorial Fund (UK), and the Percy Sladen Memorial Fund (UK). Additional equipment was provided by Idea Wild (USA). We are grateful to Henk van der Werff (MO) for his valuable comments and review of an earlier version of this manuscript. We thank reviewers Jens Rohwer and Pedro Luís Rodrigues de Moraes for their helpful corrections and comments on the manuscript submitted for publication. Teri Bilsborrow, Mary Merello, and James C. Solomon are gratefully acknowledged for their logistical herbarium support at the Missouri Botanical Garden.