Caladium praetermissum [Bogner & Hett. ]

Caladium praetermissum

General description:

Evergreen herb. Underground part a thick rhizome, 3.5-18 cm long and 2.5-8.0 cm in diam., suberect to erect, outside brown, producing few short rhizomatous offsets. Petiole nearly terete, the ventral side somewhat flattened, 34-108 cm long and (.5-) .7-1.5 cm in diam., uniformly purple-colored or purplish, only the upper part slightly paler; sheath 10-35 cm long. Leaf blade cordate-peltate, membranous, 21-42 cm long and 14-31 cm wide, pale green to mid green, with larger, irregular cream-colored to somewhat greyish spots (spots darkening with age of the leaves) on upper surface, lower surface much paler; spots translucent, apex cuspidate, basal lobes 6-13 cm long and rounded, sinus (at base) v-shaped and 4-10 cm deep, insertion of petiole 2-3 cm below the sinus, venation reticulate, midrib strong, on each side with 6-8 primary lateral veins, the two basal ones running into the basal lobes and divided at nearly a quarter to a third of their length and then further divided, main venation on both sides pale green to purplish tinged, second order veins between the primary ones thinner and forming an interprimary collective vein, third order veins much thinner and anastomosing, the primary lateral veins terminating in a collective vein along the margin in a distance of 1-3(-4) mm of it, marginal vein thin and inconspicuous. Cataphylls 13-19 cm long. Peduncle ca. 25 cm long and .3-.4 cm in diam., same color as petiole. Spathe 10 cm long, only very slightly constricted, limb of spathe cream-colored, apex mucronate, ca. 3 mm long. Spadix much shorter than spathe, ca. 5 cm long; female zone ca. 2 cm long and 6 mm in diam.; sterile zone with synandrodes between female and male flowers .8-1.0 cm long and ca. 2 mm in diam.; male zone 1.8-2.0 cm long and ca. 3 mm in diam., fertile to apex, apex acute. Flowers unisexual, naked. Female flowers densely arranged, stigma orbicular, nearly as broad as ovary, .9-1.0 mm in diam., slightly depressed in the center. Synandria somewhat densely arranged, lower ones more or less elliptic and upper ones lobed in upper view, .7-.8 mm in diam., thecae lateral. Synandrodes loosely arranged, subclavate to peltate, ca. .8 mm long and stipe ca. .3 mm in diam., widened at top and there ca. .5 mm in diam., flattened, orbicular in upper view. Infructescences unknown. Chromosomes: 2n = 28.

General Description Reference:

W. L. A. Hetterscheid, Josef Bogner, J. Boos, 2009. Two New Caladium Species (Araceae)

Misc

Cultivation:

C. praetermissum is an evergreen herb which grows well in a pot in light, humus-rich soil but needs warm (greenhouse-) conditions. In Munich one group of this species grows in a peat swamp in a stove house and these specimens are two to three times bigger than those growing in pots. Cultivated plants usually possess three to four leaves simultaneously.

Cultivation Reference:

W. L. A. Hetterscheid, Josef Bogner, J. Boos, 2009. Two New Caladium Species (Araceae)

Taxonomy

Taxonomic Notes:

Note 1: It is not clear why this plant is identified in cultivation as an Alocasia because all species of that genus possess a sterile appendix which is easily observable. Furthermore the leaves of the genus Alocasia are usually coriaceous but membranous in Caladium.
Note 2: C. praetermissum is similar to C. bicolor (Aiton) Vent. in habit but differs in sprouting from a thick underground rhizomatous stem, in having pale green leaf blades with larger, white or more or less cream-colored spots and especially in having clavate synandrodes between the female and male flowers, orbicular in upper view, which in C. bicolor are respectively flat and sessile and in upper view elongate. Caladium praetermissum can easily be distinguished from other species of this genus by the clavate synandrodes which are orbicular in upper view and by a leaf blade proportion with a length/width ratio of ca. 3:2. Additionally it can be distinguished from the other new species presented here, Caladium clavatum, by the latter possessing leaf blades which are nearly as long as wide, ca. 1:1, and the latter growing from a depressed globose tuber. Furthermore, both species also differ from C. bicolor in their color, Caladium praetermissum having pale green leaf blades with larger cream-colored spots and C.. clavatum having leaf blades with a reddish to violet tinge, with the veins more or less deeper red to purple and the large spots pale reddish pinkish colored.
Note 3: When all plants in cultivation are derived vegetatively from one clone, the latter may then be regarded as a cultivar, which should carry the name C. praetermissum 'Hilo Beauty' or C. 'Hilo Beauty' (the cultivar epithet established by Graf, 1982 as part of the name Aloeasia 'Hilo Beauty').
Note 4: The natural distribution of C. praetermissum remains a mystery. In the general area of Hilo on Hawaii, plants are found with leaves similar to C. praetermissum but smaller, broader and thicker. These plants usually show a tuber shape typical for C. bicolor but every now and then specimens are found with a more elongate, rhizome-like tuber (pers. comm. P. Resslar, USA). These plants are also said to resemble C. marmoratum Mathieu, a species described from Ecuador. It needs further study to establish if C. praetermissum is an aberrant offshoot of these plants around Hilo. The name Caladium marmoratum stands for a form of C. bicolor with the typical flat and elongate synandrodes, as could be observed from a redrawing at Kew of the original illustration, and is therefore not applicable to the species described here. In any case, however, the cultivar name Caladium 'Hilo Beauty' would be appropriate since a cultivar name only requires a genus name and the cultivar epithet.

Taxonomic Notes Reference:

W. L. A. Hetterscheid, Josef Bogner, J. Boos, 2009. Two New Caladium Species (Araceae)

CATE Araceae

Araceae

Caladium praetermissum Bogner & Hett.

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