Christiana eburnea Kubitzki
Creators: name: Coutinho, Thales Silva
name: Barbosa-Silva, Rafael G.
name: Dorr, Laurence J.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malvales
Malvaceae
Christiana
Christiana eburnea

description: 2.Christiana eburnea(Sprague) Kubitzki, Bot. Jahrb. Syst. 116 (4): 541. 1995.
Fig. 2
Asterophorum eburneum Sprague, Bull. Misc. Inform. Kew 1908 (6): 249. 1908. Type. Ecuador. Guayas: Chonona [“ Chonana ”] near Guayaquil, Dec 1861 (fl), R. Spruce 6260 bis (lectotype, here designated: K [K 000381141]!; isolectotype: K [K 000381140]!).
Type.
Based on Asterophorum eburneum Sprague.
Description.
Trees, 4–5 m tall. Leaves: petioles 1.8–3.7 cm long, leaf blades 15.5–40.5 × 7.5–18 cm, ovate, discolorous, bases truncate to subcordate, margins entire, apices acuminate, stellate trichomes above and below. Inflorescences long peduncled; flowers on second order axes. Capsules syncarpous, 2–2.5 cm long, subturbinate to turbinate, wings inconspicuous.
Distribution and habitat
(Fig. 2). Endemic to Ecuador at 590–610 m elevation. Christiana eburnea occurs in areas of mangrove with influence of Savanna and Deciduous Forest. The report (Dorr 1999) of C. eburnea occurring in Peru was based on the misidentification of a specimen (Schunke V. 5516) properly referred to C. mennegae (Jans.-Jac. & Westra) Kubitzki as reported by Barbosa-Silva et al. (2021).
Phenology.
Flowering specimens collected in December and fruiting in August.
Conservation status.
Christiana eburnea is known from two localities, with only one specimen found within a protected area (Reserva Ecológica Manglares Churute). With an AOO of 8 km 2, this species is assessed here as Critically Endangered (CR), under B 2 ab (ii, iv, v) criteria, according to IUCN (2012).
Vernacular names.
Unknown.
Etymology.
From the Latin ‘ eburneus, eborinus ’ meaning ivory-white with yellow tinge, a reference to the petal color according to the protologue.
Additional specimens examined.
Ecuador. Guayas: Naranjal, Reserva Ecologica Manglares – Churute, cerca a la Cumbre del Pancho Diablo de frente al Puerto de Gallo, 590 –– 610 m, 02 ° 25 ' S, 079 ° 35 ' W, 13 Aug 1992 (fr), C. E. Cerón 20141 (US [00976599]); Ad fluvium Daule prope Guayaquil, s. d. (fl, fr), R. Spruce 6260 (BM [BM 000554440; digital image], G [G 00356894], MPU [MPU 015290; digital image], P [P 02143013], W [1889-0106457]); Guayaquil, s. d. (fr), R. Spruce 6260 (P [P 02143014]).
Discussion.
Christiana eburnea is recognized by its fasciculate inflorescences with flowers arranged on second order axes and subturbinate to turbinate capsules, features that differentiate it from C. restingae.
This species was described as a novelty discovered in the Kew Herbarium (K) and its protologue states “ Ecuador. Chonana [sic] near Guayaquil, Spruce 6260. ” A specimen in Herbarium Hookerianum (K) labeled by Sprague “ Asterophorum eburneum, Sprague nov. gen et sp. Brownlowiearum ” has Sprague’s notes and sketches and the exact locality cited in the protologue but it is numbered “ 6260 bis. ” This specimen most closely matches the information given in the protologue and is designated here as the lectotype. We imagine that Sprague either miscopied the collection number or the word “ bis ” was added to the label later. Another specimen in Herbarium Hookerianum (K), also labeled by Sprague, has a copied label with the locality “ prope Guayaquil ” and the number 6260 bis. It clearly is a duplicate of the former.
Additional Spruce material (BM, G, MPU, and P) labeled “ Ad fluvium Daule prope Guayaquil ” has the number “ 6260 ” as cited in the protologue but this material lacks the precise locality that was given even though Chonona, an indigenous locality, eventually was subsumed by the municipality of Daule (Jijón y Camaño 1919). Given the locality conflict, these specimens are considered original but not type material. Finally, two herbarium sheets of Spruce 6260 in Paris (P 02143014 and P 02143015) lack original labels yet have Baillon’s sketches and notes; the latter sheet consisting of notes only.
description: Published as part of Coutinho, Thales Silva, Barbosa-Silva, Rafael G. & Dorr, Laurence J., 2025, A synopsis of Christiana DC. (Malvaceae, Brownlowioideae), with a new species from the Brazilian Atlantic Forest, pp. 33-56 in PhytoKeys 253 on pages 33-56, DOI: 10.3897/phytokeys.253.145350