Erisma calcaratum (Link) Warm.

• Authority

  Andersson, Lennart. 1998. A revision of the genus (Rubiaceae--Cinchoneae). Mem. New York Bot. Gard. 81: 1-75.

• Family

  Vochysiaceae

• Scientific Name

  Erisma calcaratum (Link) Warm.

• Description

  Species Description - Tree 10-20 m high, to 40 cm dbh; hairs where present grayish-tomentose. Leaves opposite; blade coriaceous, elliptic or narrowly elliptic, 12-28 X 4.5-11.5 cm, glabrous; apex acute or acuminate; base obtuse, rounded or subcordate; midvein prominent on both surfaces of the leaf; lateral veins 7-9 pairs, prominent on both surfaces, angle with midvein 60- 70°, anastomosing irregularly; tertiary veins percurrent, sinuous, approx, at right angles and oblique to midvein, arrangement alternate and opposite; petiole terete, 5-10 mm long; stipules subulate, ca. 3 mm long. Inflorescences terminal, 16.5-23 cm long, pe¬duncles and lateral branches densely pubescent; cincinni 1.5-4 cm long outer bracts oval-orbicular, ca. 2X2 mm, deciduous; inner bracts linear, ca. 1 mm long; pedicel 1-2 mm long; buds 10-13 mm long; spurred calyx-lobe ca. 10 X 10 mm, spur conical, 5-6 mm long, incurved; other calyx-lobes 7-9 mm long; petal blue or purplish, ca. 15 X 15 mm; stamen ca. 9 mm long; staminodes 1-3, 1-5 mm long, style ca. 9 mm long, pilose at base. Fruits without wings, woody, longitudinally ridged, rugose, 5.5-6.5 x 2.5 - 3 cm, glabrescent.

• Discussion

  Local names. Venezuela; chimaco (Bare lan¬guage). Peru: cacahuillo, sacha caca-huillo. Brazil: aburana, cachimbo-de-jaboti, jaboti. jaboti-da-var- zea, vergalhao-de-jaboti.

  Erisma calcaratum is the only species of the genus typical of inundated forests, both in varzeas and igapos, and with wingless fruits that float and are dispersed by water. The species was originally de¬scribed in Qualea of the tribe Vochysieae (Link, 1820). This tribe is characterized by genera with superior, trilocular ovaries and dehiscent fruits. However, E. calcaratum undoubtedly belongs to the tribe Erismeae because of its inferior and unilocular ovary and indehiscent fruits. The unusual and distinct fruits of this species were unknown until they were described by Ducke in 1922.
  This species is also characterized by the prominent midvein on the upper surface of the leaves, the grayish inflorescences, the large buds with incurved spur, and the purple flowers. Erisma calcaratum and E. uncinatum are by far the two most common species of the genus, widely distributed throughout the Amazon Basin. Within the genus, the grayish inflorescences with purple flowers are found only in these two species, which are, however, unrelated species distinguished by habitat, leaf venation, spur shape, and fruit morphology. Erisma calcaratum is closely related to E. micrart- thum, as already mentioned by Warming (1875), and it also shows affinities with E. japura. It is similar in leaf morphology to E. blancoa, which is, however, an unrelated species. The differences among E. calcaratum, E. micranthum, E. japura, and E. blancoa are summarized in the key to the species.