Syagrus × tostana (Bondar) Glassman (1963: 261)

Noblick, Larry R., 2017, A revision of the genus Syagrus (Arecaceae), Phytotaxa 294 (1), pp. 448-450 : 448-450

76. Syagrus × tostana (Bondar) Glassman (1963: 261) ( S. schizophylla × S. coronata ). Cocos × tostana Bondar (1942a: 458) . Arikuryroba × tostana (Bondar) Hawkes (1952a: 175) . Lectotype (designated by Glassman [1987: 88]):— BRAZIL. Bahia: near Pituba, Salvador [–13.00, –38.46], 1940, G. Bondar s.n. (F! [F–619775])

Figure 90 map.

Moderate, solitary, unarmed, palms. Stem erect, 2–3(–7.5) m × 10–15(–20) cm, with leaf scar intervals obscured by persistent petiole bases. Leaves 8–15, spirally arranged, stiff, erect–ascending; sheathing leaf base ca. 15–18 cm wide, broad, with unusual spines along the margins diminishing upward; pseudopetiole 100–116 cm long, but with margins with long, flat, spine–like projections for half its length, dentate beyond this point, and finally becoming devoid of spines for the last 10 cm, petiole ca. 10 cm long; rachis 210–220 cm long; leaflets bright green (not grayish) adaxially, paler abaxially, ca. 65 along one side, irregularly distributed, divergent in pairs on the lower half of the leaf, regularly distributed, lying in one plane on the upper half; basal leaflets not measured, middle leaflets 70–80 cm (most shorter) × 3.5–4 cm, apical leaflets not measured, mostly with acuminate tips. Inflorescence erect to pendulous, spirally branched; prophyll not measured; peduncular bract ca. 120–140 cm long, expanded portion 82–97 × 10 cm, woody, sulcate; peduncle ca. 70–80 × 1.5–2.5 cm, elliptical in crosssection; inflorescence axis 79–94 cm long; rachis ca. 50 cm long; rachillae 60 or more, 40–45 cm long at the base; rachillae bracts absent or to 2 mm long; staminate flowers 8–11 mm long at the apex, 11–14 × 3–5 mm at the base, yellow, sepals 1–2 × less than 1 mm, petals 6–9 mm long at the apex, 9–12 × 2–3 mm at the base with acute tips, nerves indistinct, stamens not measured, anthers 5–6 mm, filaments 3 mm long, attached to the basal 1/3 of the anther, pistillode 1–1.5 mm; pistillate flowers 10–11.5 × 6–8 mm, light greenish yellow, sepals 10–11 × 6–8 mm, petals 7–8 × 4–5 mm, pistil 5 × 3–4 mm, stigmas 2–2.5 mm long, staminodal ring ca. 1 mm high. Fruit ellipsoid, 3–4 × 2.3–2.6 cm, persistent perianth (cupule) light gray brown, 17–19 mm wide, 8–10 mm deep, ring 2–3 mm in height, epicarp fleshy and having a short beak, orange–red when fruit is mature, less than 1 mm thick, mesocarp 2– 3 mm thick, fleshy or succulent, fibrous pulpy, mucilaginous, sweet–tasting; endocarp 3–4 × 1.8–2.0 cm, 2–3 mm thick on the sides, up to 7 mm thick at ends, bony, trivittate, with no clusters of fibers; seeds 1.7–2.1 × (0.8–) 1.1– 1.3 cm, endosperm homogeneous.

Common name:— licurioba–açú, licurioba-assú, licuriroba-ussú.

Etymology:— The specific epithet, tostana , honors Dr. Ignacio Tosta Filho, in admiration for his dedication to the progress of Bahia and gratitude for an old friendship. ( Bondar 1942b).

Distribution and habitat:— Endemic to the Brazilian state of Bahia in the coastal restinga found wherever the ranges of S. coronata and S. schizophylla overlap. This range occurs in the restinga areas along the coast, from Salvador, Bahia to Sergipe. The original specimen was described from Pituba, a barrio or suburb of Salvador, Bahia. The only natural occurring specimen (the type) was collected in restinga vegetation in loose sandy soils.

Phenology:— This hybrid palm flowers in November.

Uses:— May have ornamental potential.

Notes:— Syagrus × tostana is the hybrid between S. coronata and S. schizophylla . It differs from S. coronata by having green leaves instead of grayish–green like the former, by the irregularly arranged leaflets which diverge very little from one another in the basal part of the leaf blade becoming more regularly arranged and lying in one plane in the upper half, and by having the leaves arranged in distinct spirals on the trunk rather than in five rows as seen in S. coronata . The fruit is larger than either one according to Bondar and the endosperm is homogeneous; not ruminate. Another difference mentioned by Bondar was an internally marked trivittate endocarp, instead of a "monovittate" one as seen in S. coronata , but in reality S. coronata 's endocarp is also trivittate.

A REVISION OF THE GENUS SYAGRUS

Phytotaxa 294 (1) © 2017 Magnolia Press • 235

This hybrid differs from S. schizophylla by being more robust with a thicker stem, the leaves are stiffly erect and not arching, the petioles of the leaves are wider at their bases; petiole margins with angled spines on the lower portions of the petiole, which disappear and become smooth for a short distance before the insertion of the first leaflets. The inflorescences are more robust, and staminate flowers are larger. The endosperm is homogeneous in this hybrid, but ruminate in S. schizophylla .

In Brazil, this is a very rare hybrid, which may be found wherever the ranges of S. coronata and S. schizophylla overlap in the restinga areas along the coast. The original specimen was described from a barrio of Salvador (Pituba). Bondar (1942a) wrote that he only saw two specimens, one in the backyard of a private residence in Barra, a barrio of Salvador, and the other (the type collection) on the fazenda Pituba, as mentioned above. After an intensive search, the author was unable to find any specimens near Salvador, which has experienced tremendous urban growth in recent years. Some specimens are reported to have been recently seen from Sergipe (Medeiros-Costa, pers. comm.)

Specimen examined:— Known only from the type, BRAZIL. Bahia: Salvador, Pituba, 1940, G. Bondar s.n. (F-619776) .

Figures

FIGURE 90. Distribution map of Syagrus hybrids. S. × altopalacioensis, S. × andrequiceana, S. × campos-portoana, S. × cipoensis, S. comosa × elata, S. × costae, S. × lacerdamourae, S. × matafome, S. × mirandana, S. × serroana, S. × teixeiriana, and S. × tostana.