Cinnamomum bladenense S.W. Brewer & G.L. Stott, 2017

Brewer, Steven W. & Stott, Gail L., 2017, A new species of Cinnamomum (Lauraceae) from the Bladen Nature Reserve, southern Belize, PhytoKeys 81, pp. 1-10 : 1-2

Cinnamomum bladenense S.W. Brewer & G.L. Stott sp. nov.

Type.

BELIZE. Toledo District: Bladen Nature Reserve, c. 11 km north of Medina Bank , 16°33.14'N, 88°43.825'W, 320 m, 2 February 2016, S. W. Brewer & G.L. Stott 7529, (holotype, MO!; isotypes BM!, BRH!, CICY!, MO!, NY!, XAL)

Diagnosis.

Cinnamomum bladenense is morphologically similar to Cinnamomum brenesii (Standl.) Kosterm. from which it differs by its much smaller (c. 2.1 vs. 3 mm long) and campanulate (vs. urceolate) flowers, its inner tepals glabrous abaxially (vs. pubescent), its shorter petioles (<10 vs.> 10 mm), its moderately and minutely sericeous (vs. tomentose) younger twigs, and its abaxially matte green (vs. light-green glaucous) mature leaves with clearly prominent secondary venation abaxially (vs. venation nearly plane with the lamina).

Description.

Tree 25 m tall, 26 cm DBH; bole round and mostly straight, with a low, narrow buttress of irregular-sized planks (Figure 2 ). Outer bark smooth, light-to-medium gray with a pinkish cast, occasional eye marks and rings, and lines of inconspicuous lenticels oriented lengthwise. Inner bark pinkish-brown with a moderately-pungent, chemical odor like that of bathroom cleaner (volatile, soapy).

Terminal buds moderately to densely sericeous with yellowish-white hairs. Twigs with slender, parallel, longitudinal grooves & low ridges (striate) to striate-angulate, less frequently laterally compressed and ridged-angulate, thinly to moderately-densely, minutely sericeous with silvery-white to yellowish, straight or weakly curved hairs 0.04-0.20 (0.3) mm long. Leaves alternate, thick-chartaceous to sub-coriaceous, ovate to ovate-elliptic, apex acute to shortly acuminate (rarely obtuse or rounded), base acute; within-branch leaf sizes highly variable, 11-31 mm wide × 35-86 mm long; petioles 3-9 mm, broadly and shallowly canaliculate, minutely sericeous. Venation mostly triplinerved, some subtriplinerved, the basal lateral nerves reaching c. ½ to ⅔ the length of the lamina; secondary veins 6-8; midvein and secondary veins immersed above, higher-order venation minutely impressed; midvein and secondary veins prominent below, higher order venation prominulous or minutely so. Inconspicuous domatia present in the form of barbellate axils of the basal-most pair of secondary veins, plane with the lamina, and usually present in one or two additional axils along the midrib, (rarely absent from a leaf). Laminae adaxially glossy, medium-dark green, glabrescent, with minute, mostly appressed to spreading, undulate to crisped, white to yellow-brown hairs on the basal portion of the midvein. Abaxial laminae light green, matte (to thinly and inconspicuously glaucous on young leaves), glabrescent or with very thinly-scattered, minute, subappressed and weakly undulate hairs; mid and lateral veins typically thinly minutely sericeous with appressed to subappressed hairs.

Inflorescences paniculate-cymose in leaf axils, 40-80 (130) mm, axes moderately covered in minute, mostly appressed (to spreading), straight to crisped hairs; bracts ligulate, mostly deciduous, to c. 5 mm long. Flowers narrowly campanulate, c. 2.0 mm long, on pedicels (2.0) 2.3-2.8 (-3.4) mm, drying dark brown to blackish-brown. Tepals 6, abscising nearly to the base in fruit, in flower spreading at shallow angles to the flower’s long axis, glabrous abaxially, sericeous adaxially, the margins basally ciliolate, ovate to broadly elliptic, outer c. 1.9 mm and inner c. 2.3 mm × c. 1 mm. Stamens 9, 0.8-1.4 mm, all four-celled, filaments pubescent on both surfaces, inner three with sub-globose glands at the base; staminodia 0.8-0.9 mm, filaments pubescent, heads cordate, to 0.5-0.6 × 0.3-0.4 mm. Pistil 1.1-1.9 mm, the style c. 10% longer than the ovary. Hypanthium sericeous inside, glabrous outside. Immature fruits thinly-glaucous green or green, ellipsoid to 10.3 × 6.0 mm. Cupules to 4.5 × 3.8 mm, tepal remnants inconspicuous, to 0.26 mm above the bottom of the sinus between tepal remnants, pedicels partly turbinate in fruit (Figure 4 ).

Other specimens examined.

Brewer & Stott 7148 (from the same individual as the type, in sterile condition, collected in March 2014), Brewer & Stott 6815 (sterile tree 15 m tall, 12 cm DBH, collected in December 2012).

Etymology.

The specific epithet honors the type location, the Bladen Nature Reserve, established in 1990 (IUCN Category 1a) to protect the watershed and the unique flora and fauna of the Bladen branch of the Monkey River. The origin of the word “Bladen” is unknown.

Phenology and reproduction.

Phenology data for this species are few; currently, flowering in this species is known to begin with the onset of the dry season, December-January, with fruits developing in January and February. The trees are not known to be fertile below 15 cm DBH and are not fertile every year.

Distribution and ecology.

Cinnamomum bladenense is currently known only from fewer than 10 individuals on two limestone ridge-and-knoll systems south of the Bladen branch of the Monkey River, a few km upstream from where the Bladen descends into the coastal plain. This canopy tree species occurs in semi-evergreen forest c. 25 m high on very-well-drained, steep and rocky slopes on Cretaceous limestone. Similar habitat occurs southwest of the type location nearly to the Guatemala border, and northeast of the type location to the southeastern portion of the Cockscomb Basin, along the southeastern foothills of the Maya Mountains.

Preliminary conservation assessment.

Population information is too limited to support an assessment of the extinction risk faced by Cinnamomum bladenense , and the category of Data Deficient (DD) is appropriate, according to IUCN (2012) criteria. The known habitat of the species is protected as part of a nature reserve, however anthropogenic fires and illegal logging in the area, including nearby potential habitat, are potential risks to the persistence of this species.

Figures

Figure 2. A Lower trunk and buttress of Cinnamomum bladenense B Bark and shallow trunk slash. Photos of same individual tree as Brewer & Stott 7529 by SW Brewer 18 March 2014.

Figure 4. Diagnostic and other fertile characters of Cinnamomum bladenense A Axillary inflorescences on dry branch with all but one leaf removed to show variation in size and degree of branching B Apical portion of inflorescence showing flowers in bud and anthesis C Leafy branch with infructescence D Immature fruits with cupules showing partially turbinate pedicels, remnants of tepals at summit of the cupule, cupules turning red. Photos from Brewer & Stott 7529 by SW Brewer 2 February 2016.