Monday, 29 December 2008

Ficus conundrum

What is the real identity of this Ficus?
There are a number of very similar giant Ficus grown in Spain and Portugal. Sorting them out is quite complicated. Most of the trees in Lisbon are Ficus macrophylla. But this tree at Monserrate is something else!
It is not just at Monserrate that these strangler figs have botanists in a fix. The Ficus magnolioides of Borzi has been a source of considerable confusion. This was finally sorted out relatively recently: S. Fici, F.M. Raimondo, ON THE REAL IDENTITY OF FICUS MAGNOLIOIDES in Curtis's Botanical Magazine vol: 13 nº2, p.105 ,1996.
The correct name of Ficus magnolioides Borzì var. magnolioides (Moraceae) is F. macrophylla Desf. ex Pers. subsp. columnaris (C. Moore) P.S. Green. This name is derived from C. Moore's Ficus columnaris C. Moore & F. Muell., an endemic Fig of the Lord Howe Island which Fici et al identified as a subspecies of Ficus macrophylla of the Australian Mainland (Moreton Bay Fig). The subspecies is distinguished by its abundant aerial roots. Ficus macrophylla has little or no development of aerial roots.
The "Banyan" fig growing on the Chapel is currently labelled as Ficus macrophylla. Significantly the name in Spanish is given as "Ficus de Hojas de Magnolia" - a throw-back to the days when this fig was known in Southern Europe as Ficus magnolioides. However, Walter Oates in his description of the Chapel in 1929 describes a large spreading Ficus rubiginosa in its place.
What is the true identity of this Fig?
Árboles en España : Manual de identificación (Antonio López Lillo & José Manuel Sánchez de Lorenzo Cáceres)
Ficus macrophylla Desf. ex Pers.
Ficus magnolioides Borzi
Árbol corpulento de más de 15 m de altura, con copa amplia y tronco grueso. Las raíces superficiales se extienden en una gran zona alrededor del árbol. Hojas oblongo-ovadas de 20 x 12 cm, con el ápice obtuso o ligeiramente acuminado y la base redondeada. Nervio central destacado. La textura es coriácea y la superficie es glabra, de color verde oscuro en el haz, mientras que el envés es claro y cubierto de una pubescencia rubiginosa. Pecíolo de 10-15 cm de longitud. Frutos axilares, ovales u oblongo-esféricos, de 1-2 cm de diámetro, con pedúnculo de 1-1.5 cm de longitud. En la madurez son de color púrpura con manchas amarillentas. Árbol nativo de Austalia. Frecuente en ciudades de toda la zona Mediterránea, donde llega a alcanzar notables portes. En el Jardin Botánico de la Orotava (Tenerife) se cultiva la subespecie columnaris (=F. columnaris C. Moore), caracterizada por la emisíon de raíces aéreas que van fomando columnas de apoyo a las ramas. Esta subespecie es nativa de la isla de Lord Howe (Mar de Tasmania).
This description is sufficiently detailed by which to exclude the Monserrate tree in a number of aspects:
1. There are no superficial roots. (The butress roots are the great distinguishing character from a layman's point of view.)
2. The leaves are much smaller than 20 cm x 12 cm.
3. The petioles are much shorter than 10-15 cm.
4. The fruits do not have peduncles (stalks) of 1-1.5 cm.
From the same manual a description of
Ficus rubiginosa Desf. ex Vent.
Ficus australis Willd. non Hort.
Árbol de 8-10m de altura en nuestro clima mediterráneo, con la copa denas y a parasolada. Yemas pubescentes. Hojas elíptico-ovales de 5-15 x 6 cm, con el ápice obtuso y la base redondeada. Son de textura coriácea y tienan el haz glabro, salvo en las hojas jóvenes, y el envés con densa pubescensia de color herrumbroso. Pecíolo de 2-4 cm. de longitud. Frutus axilares, sésiles o escasamente pedunculados, globosos de 1,5 cm. de diámetro, cubiertos de pubescencia herrumbroa. Árbol nativo de Australia. Existe una forma variegada. Es árbol frecuente en Canarias y en todo el litoral mediterráneo, donde pueden verse notables ejemplares. Existe una forma glabra sin tomenta alguno en hojas y frutos, Australis.
From this description the leaves and fruits fit the Monserrate tree. However there is no mention of the most striking characteristic : the aerial roots! This is most probably since the authors are describing Ficus rubiginosa from dry climates - like the Canary Islands. In its Australian habitat this species produces abundant aerial roots, trees growing in the relatively humid climate of Madeira are also prolific in this aspect.
Other candidates: "On Lord Howe Island, a rare fig, Ficus columnaris, sends roots down from the branches which reach the ground and become new trunks, and so the tree walks in all directions until it becomes a small forest. Several of the more tropical banyans also walk in this way, including Australia's Ficus virens [leaves like a poplar], India's Ficus retusa [leaves like Ficus benjamina] and Ficus benghalensis [distintive and characteristic leaves] and the aptly named Ficus polypoda [Sorry Russell but this must be F. platypoda - no indumentum to leaf backs]. A famous ancient Ficus benghalensis near Poona in India has hundreds of trunks and a circumference of a kilometre". (Russell Fransham)
None of the above.
So what about Ficus rubiginosa? does it have aerial roots?
Edward F. Gilman and Dennis G. Watson of the University of Florida state in their paper on this species that "it does not develop the profusion of roots that some other [ficus] do." disagrees:
Ficus rubiginosa Deaf. ex Vent., lard. Malm. t. 114. 1805. Benth. & Mueller, Fl. Aust. 6: 173. 1873; Bot. Mag. 56: t. 2939.1829; Parker, l.c. 481. 1956; in Gard. Bull. Singapore 21(1): 26. 1965. Engl. Vern.: The Port Jackson Fig; Rusty Fig; Little Leaf Fig.
A large tree with wide spreading crown and hanging aerial roots. Young shoots rusty-pubescent. Leaves with 1-3 cm long petiole; lamina coriaceous, elliptic-oblong, 6-10 cm long, 4-8 cm broad, 3-costate at the rounded or ± base, margins entire, obtuse-acuminate at the apex, glabrous above, rusty pubescent to glabrescent beneath, lateral nerves 10-12 pairs, intercostals stipules lanceolate, acuminate. Hypanthodia in axillary pairs on c. 2.5 thick peduncles, globose, c. 8-10 mm in diameter, rusty-pubescent, by broad, membranous, c. 4 mm long, deciduous basal bracts. Male flowers: suimerous, intermixed with the female flowers; sepals 3, brown; stamen Ovary with a long, lateral style and short, acute stigma. Figs globular, in diam., rusty pubescent to glabrescent, warted.
The Australian National Botanic Garden has a series of photographs of native Ficus posted online:
Ficus macrophylla
Long petioles to leaves, long peduncles to figs, colour of fruits.
Ficus macrophylla subsp. columnaris
Note the long petioles to the leaves
Ficus platypoda
Here is another contender - but the leaf backs are green without rusty indumentum.
Ficus rubiginosa
Small leaves, sessile fruits, rusty leaf backs
Ficus rubiginosa habitat photo
Photo T.M. Tame ©Royal Botanic Gardens & Domain Trust, Sydney Australia
Ficus rubiginosa - cultivated specimen in Japan
Well my vote is still with Walter Oates : Ficus rubiginosa.
Unless, perhaps .... it is this one!
Ficus watkinsiana

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