Luteyn, James L., et al. 1995. Ericaceae, Part II. The Superior-Ovaried Genera (Monotropoideae, Pyroloideae, Rhododendroideae, and Vaccinioideae P.P.). Fl. Neotrop. Monogr. 66: 560. (Published by NYBG Press)
Ericaceae
Arctostaphylos arbutoides (Lindl.) Hemsl.
Species Description - Erect to spreading much-branched evergreen shrubs to small trees, 1-20 m tall, to 49 cm dbh; bark peeling or shredding, gray, tan, reddish-brown, or brown; indumentum on vegetative structures variable. Leaves coriaceous to subcoriaceous, narrowly ovate to elliptic, ovate or obovate, plane or revolute, 4.8-12.4 × 1-4.6 cm, base cuneate, apex obtuse to acute, margins entire (undulate or with a few serrations), petioles 4-20 mm long. Inflorescences densely paniculate, 3.5-13.3(-18.2) cm long, indumentum variable; floral bracts narrowly ovate, nearly plane to navicular or carinate, 2.5-9.8 × 1.1-2 mm, ciliate or not; pedicels 5-8 mm long; bracteoles basal to distal, 1.7-4.1 mm long, acuminate, ciliate or not. Flowers with calyx lobes triangular to ovate-triangular, 1.7-2.5 × 1.4-2.1 mm, acute to acuminate, often ciliate; corollas greenish-white to cream, pale yellow, or white, sometimes suffused with pink, 5.7-7.8 × 3.3-6.2 mm, the lobes 0.9-1.7 × 1.42.3 mm; stamens 2.6-3.2 mm long, filaments 2.4-3.1 mm long, villous, anthers 1.1-1.5 × 0.60.9 mm, spurs 0.4-1 mm long; ovary glabrous or pubescent; style 2.5-4.3 mm long, glabrous. Fruit 5-7 mm in diam., red when immature, dark purple to black at maturity; seeds 2.1-2.8 x 1.1-1.5 mm, surface reticulate.
Comarostaphylis arbutoides is a variable taxon distinguished by its entire, rather large leaves, usually densely paniculate inflorescences, and southern distribution. It is composed of two subspecies: the widespread variable subsp, arbutoides and the locally endemic subsp, costaricensis. The two differ primarily in characters of pubescence, with the glabrous twigs, petioles, and abaxial leaf surfaces of subsp. costaricensis making it immediately recognizable.Lectotypification for Comarostaphylis arbutoides was somewhat problematic. Lindley’s (1843) protologue states that the plant described was grown in the garden of the Horticultural Society of London from seed collected by Hartweg at Xetic, near Quezaltenango, Guatemala. The only possible type material of C. arbutoides in the Lindley Herbarium (CGE) is labeled "No. 871, Quezaltenango, Guatemala Hartweg." It lacks Hartweg’s usual herbarium label, and the number, 871, does not correspond with the usual numbering of Hartweg’s herbarium collections. It is thus not clear whether the specimen is from garden-grown material or if it was collected in Guatemala by Hartweg and distributed with the seeds. P. D. Sell’s annotation (1979) on the sheet reads: "Following his usual practice, Lindley would almost certainly have described this species from cultivated plants in the Horticultural Society’s Garden. He usually pressed a specimen of the plant described, sometimes the actual one that was illustrated. In this case there is no such specimen in his herbarium. This specimen of Hartweg was probably sent with the seeds that were grown by the Horticultural Society and would have been available to Lindley when he drew up the original description. It can thus be regarded as a syntype. In my opinion however, it would be safer to select the Bot. Reg. plate as the lectotype." Why Sell rejects the specimen as coming from the garden is not evident. In any case, both the fact that it is a Hartweg collection (herbarium specimen or from seed) from the type area and the fact that it is from Lindley’s herbarium certainly argue for its designation as the lectotype over the illustration. Because it is not clear whether Hartweg 871 is the exact specimen on which Lindley based his description, it is here designated the lectotype.
Distribution and ecology: Comarostaphylis arbutoides is a widespread, morphologically variable species occurring from central Chiapas in Mexico through Guatemala, Honduras, Nicaragua, and Costa Rica, reaching its southern limit in W Panama. This is the southernmost occurrence of the genus. The species occurs over a wide range of elevations, from ca. 1350 to 3800 m. Comarostaphylis arbutoides is an ecologically variable species found in habitats ranging from dry to moist Quercus or Pinus forests to other moist montane or us forests to other moist montane or cloud forests, and is also a component of the paramo vegetation on summits of the higher volcanoes of Central America. Comarostaphylis arbutoides is often an understory species but can sometimes be important in succession. In other cases, as on volcanic summits, it can be a vegetational dominant. Associates include Arbutus xalapensis, Clethra sp., Chusquea subtesselata, Magnolia sp., Pernettya prostrata, Pinus sp., Quercus costaricensis, and Vaccinium consanguineum. Several collections are known from limestone areas. Flowering and fruiting throughout the year. The epithet is based on resemblance to the genus Arbutus, the madrones. Comarostaphylis arbutoides is a variable taxon distinguished by its entire, rather large leaves, usually densely paniculate inflorescences, and southern distribution. It is composed of two subspecies: the widespread variable subsp. arbutoides and the locally endemic subsp. costaricensis. The two differ primarily in characters of pubescence, with the glabrous twigs, petioles, and abaxial leaf surfaces of subsp. costaricensis making it immediately recognizable. Lectotypification for Comarostaphylis arbutoides was somewhat problematic. Lindley's (1843)
Mexico North America| Guatemala Central America| Honduras Central America| Nicaragua Central America| Costa Rica South America| Panama Central America|