Williamodendron itamarajuensis P.L.R.Moraes, 2017

Moraes, Pedro Luís Rodrigues De, Vergne, Matheus Carvalho & Werff, Henk Van Der, 2017, Three new species of Lauraceae from the Atlantic rainforest of Brazil, Phytotaxa 316 (2), pp. 149-160 : 157-159

Williamodendron itamarajuensis P.L.R.Moraes , sp. nov.

Type:— BRAZIL. Bahia: Itamaraju, estrada Itamaraju–Prado km 24, 10 December 2010, fl., A. A. da Luz 515 (holotype CVRD!; isotypes HRCB! 61551, 66403, MO!). ( Figures 4 , 8–9 )

Diagnosis: —Similar to Williamodendron cinnamomeum , but differing by the habit, phenology, indument on vegetative parts, leaf reticulation, shorter leaves and petioles, longer inflorescences, inner tepals slightly longer than the outer ones, and receptacle glabrous inside.

Description: —Small tree, to 7 m. Twigs terete, tomentellous, hairs yellowish, leaf scars conspicuous; terminal buds hirsute, hairs yellowish. Leaves alternate, clustered toward the tips of the branches, obovate, chartaceous, 8.3–14 × 4.2–7.0 cm, base acute, often asymmetric, apex obtuse to rounded to emarginate, margin flat, sclerified; the upper surface shiny, glabrous or with tomentellous pubescence along midrib and secondary veins, midrib and secondary veins immersed; the lower surface papillate, with veins up to the third order conspicuously raised, covered by tomentellous pubescence, and by sparse, ± long, erect, yellowish hairs on the lamina, venation eucamptodromous-brochidodromous, 8–11 secondary veins on each side; petioles 0.7–4.4 cm, flat to slightly canaliculate, semiterete, with similar indument as twigs. Inflorescences paniculate, axillary, shorter than the leaves, 2.7–9.9 cm, few-flowered, glabrescent, hairs straight, appressed, short; flowers subtended by one minute lanceolate bract, pubescent, and two lanceolate bracteoles attached at the base of the pedicels; pedicels to 1.2 mm long, glabrous. Flowers greenish, glabrous, bowl-shaped, 2.9 × 2.1 mm; tepals 6, glabrous, incurved, or somewhat erect, subequal, the inner three slightly longer than the outer three, rigid, broadly ovate, tip obtuse, ciliate, inner tepals 1.0–1.2 × 1.2–1.3 mm, outer tepals 0.7–0.8 × 1.1–1.2 mm, style exserted at anthesis; stamens of whorls I and II absent; stamens of the third whorl 3, 4-locular, opposite the outer tepals, the cells apical on the flat tip of the anther, ca. 0.7 × 0.9–1.1 mm, the filaments densely pubescent, slightly narrower than the anthers; staminodia 3 (whorl IV), ca. 0.7 × 0.4 mm, densely pubescent adaxially, opposite the inner tepals; pistil glabrous, ca. 1.3 mm long, style short, ca. 0.3 mm long, ovary globose, ca. 0.9 × 0.8 mm, stigma inconspicuous, receptacle very shallow, glabrous inside. Fruits unknown.

Williamodendron itamarajuensis most likely is more closely related to W. cinnamomeum van der Werff (1991: 6) , from the Atlantic forest of Espírito Santo, rather than to its congenerics: W. spectabile Kubitzki & Richter (1987: 50) , from the Amazon region; W. quadrilocellatum ( van der Werff 1987: 176) Kubitzki & Richter (1987: 58) , from Colombia; and W. glaucophyllum ( van der Werff 1987: 164) Kubitzki & Richter (1987: 58) , from Costa Rica. Both W. itamarajuensis and W. cinnamomeum are poorly collected in flower (only one collection each), consequently resulting in incomplete knowledge of the variability they might possess. In spite of that, the differences found between them in vegetative and floral characters are strong enough to allow the identification and description of W. itamarajuensis as a different species. While W. cinnamomeum is a dominant tree up to 20 m tall, collected in flower in March, W. itamarajuensis is relatively smaller, 7 m tall, collected in flower in December. The 10 available specimens of W. cinnamomeum , collected from two different sites in the municipality of Santa Teresa, show consistent patterns of leaf indument and leaf venation, which differ from the specimen collected in Itamaraju. The leaves of the former are densely covered by an indument of cinnamon brown tomentellous hairs on the lower surface, whereas the leaves of the latter are less densely covered by a yellowish tomentellous indument. The leaf venation of W. cinnamomeum shows conspicuous raised veins of all orders on the lower surface, while the veins are conspicuously raised up to the third order in W. itamarajuensis . In addition, even taking the scarcity of collections of both species, two floral characters are distinctive between them, viz. the outer tepals slightly longer than the inner ones, and receptacle pubescent inside in W. cinnamomeum , contrasting with the inner tepals slightly longer than the outer ones, and receptacle glabrous inside in W. itamarajuensis .

Phenology: —Flowering specimen collected in December.

Etymology: —The species name refers to the locality of the type collection in Bahia.

Conservation status: — Williamodendron itamarajuensis is only known from the type collection and is assessed as Data Deficient (DD) based on the IUCN criteria ( IUCN 2010). An effort has been made to collect more specimens in the type locality, but the species was not located.

Figures

FIGURE 4. Geographic distribution of Cinnamomum baitelloanum van der Werff & P.L.R.Moraes, Mezilaurus sessiliflora P.L.R.Moraes &Vergne, and Williamodendron itamarajuensis P.L.R.Moraes.

FIGURE 8. Isotype of Williamodendron itamarajuensis P.L.R.Moraes: A.A. da Luz 515 (HRCB).

FIGURE 9. Williamodendron itamarajuensis P.L.R.Moraes. A. Flower. B. Outer tepals, abaxial and adaxial surfaces. C. Inner tepals, abaxial and adaxial surfaces. D. Stamen of whorl III, dorsal view. E. Stamen of whorl III, apical view showing the four locelli. F. Staminode, ventral view. G. Pistil. From A.A. da Luz 515 (HRCB). Bars = 1 mm (A); 0.5 mm (B, C, D, E, F, G).