Monographs Details:
Authority:
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)
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)
Family:
Ericaceae
Ericaceae
Synonyms:
Arbutus mollis Kunth, Arbutus petiolaris Kunth, Arbutus densiflora Kunth, Arbutus varians Benth., Arbutus glandulosa M.Martens & Galeotti, Arbutus floribunda M.Martens & Galeotti, Arbutus macrophylla M.Martens & Galeotti, Arbutus laurina M.Martens & Galeotti, Arbutus paniculata M.Martens & Galeotti, Arbutus texana Buckley, Arbutus peninsularis Rose & Goldman, Arbutus donnell-smithii Small, Arbutus xalapensis var. pubescens Benth., Arbutus densiflora var. petiolaris (Kunth) Loes., Arbutus xalapensis var. texana (Buckley) A.Gray
Arbutus mollis Kunth, Arbutus petiolaris Kunth, Arbutus densiflora Kunth, Arbutus varians Benth., Arbutus glandulosa M.Martens & Galeotti, Arbutus floribunda M.Martens & Galeotti, Arbutus macrophylla M.Martens & Galeotti, Arbutus laurina M.Martens & Galeotti, Arbutus paniculata M.Martens & Galeotti, Arbutus texana Buckley, Arbutus peninsularis Rose & Goldman, Arbutus donnell-smithii Small, Arbutus xalapensis var. pubescens Benth., Arbutus densiflora var. petiolaris (Kunth) Loes., Arbutus xalapensis var. texana (Buckley) A.Gray
Description:
Species Description - Trees or arborescent shrubs, 4-6 m, often up to 15 m (occasionally said to be taller); bark usually brick red and peeling in large, smooth flakes over most of the larger limbs, ceasing to exfoliate at the base of the trunk on older specimens and eventually retained over most of the oldest parts of the plant, becoming gray, irregularly roughened; twigs of newly emerging shoots usually densely villous, often with a mixture of glandular hairs, fully developed twigs pubescent and/or glandular pubescent, or glabrate to completely glabrous, twig bark soon loosening and exfoliating, older twigs usually smooth, brick-red, or glaucous grayish-red. Leaves pale or bright olive-green or glaucous-green, slightly lighter beneath, blades elliptic or slightly ovate-elliptic, (4-)5-11(-15) × 1.5-4.8(-6) cm, base tapered, rounded, sub-truncate, or slightly cordate, apex acute or obtuse; margins smooth or irregularly toothed, rarely slightly spinulose, upper surface glossy-glabrous (when fresh) or pubescent, often densely so toward base of blade and especially along the midrib, lower surface glabrous or more often pubescent, frequently white, tan, or brown woolly, sometimes with a few glandular hairs; petioles 1/4-l/3(-l/2) the length of the blade, vestiture about the same as on the blade, but glandular hairs more dense if present, these straight or curly, drying stiff, up to 1.5 mm long. Inflorescence a terminal cluster of racemes, very variable, from densely clustered or openly-branched, to few-flowered, often showy, axes including pedicels usually with glandular hairs, these sometimes copious and conspicuous. Flowers borne obliquely erect on accrescent pedicels 6-9 (-14) mm long, subtended by a reddish or tan-colored accrescent bract 2-3.5 mm long, to 4.9 mm long in fruit, enclosing 2 smaller bracteoles; calyx 1.8-3 mm long (northern material with a blush of pink), lobes often dorsally pubescent, margins scarious and ciliate or glandular-ciliate; corolla 5.1-6(-7.2) mm long, the larger on rapidly developing, more open and elongated inflorescences, inner surface of tube smooth or sparsely pubescent below the middle; filaments 2.1-3 mm long, anthers about 1.5 mm long, spurs (1/2-)3/4-4/5 the length of the thecae. Ovary with up to 10 ovules per locule. Fruit more or less spherical, or slightly turbinate, 7.5-8.8(-9) mm diam, when ripe; seeds 4 or 5 per locule, 1.8-2.5 mm long. Chromosome number 2n = 26 (Callan, 1941).
Species Description - Trees or arborescent shrubs, 4-6 m, often up to 15 m (occasionally said to be taller); bark usually brick red and peeling in large, smooth flakes over most of the larger limbs, ceasing to exfoliate at the base of the trunk on older specimens and eventually retained over most of the oldest parts of the plant, becoming gray, irregularly roughened; twigs of newly emerging shoots usually densely villous, often with a mixture of glandular hairs, fully developed twigs pubescent and/or glandular pubescent, or glabrate to completely glabrous, twig bark soon loosening and exfoliating, older twigs usually smooth, brick-red, or glaucous grayish-red. Leaves pale or bright olive-green or glaucous-green, slightly lighter beneath, blades elliptic or slightly ovate-elliptic, (4-)5-11(-15) × 1.5-4.8(-6) cm, base tapered, rounded, sub-truncate, or slightly cordate, apex acute or obtuse; margins smooth or irregularly toothed, rarely slightly spinulose, upper surface glossy-glabrous (when fresh) or pubescent, often densely so toward base of blade and especially along the midrib, lower surface glabrous or more often pubescent, frequently white, tan, or brown woolly, sometimes with a few glandular hairs; petioles 1/4-l/3(-l/2) the length of the blade, vestiture about the same as on the blade, but glandular hairs more dense if present, these straight or curly, drying stiff, up to 1.5 mm long. Inflorescence a terminal cluster of racemes, very variable, from densely clustered or openly-branched, to few-flowered, often showy, axes including pedicels usually with glandular hairs, these sometimes copious and conspicuous. Flowers borne obliquely erect on accrescent pedicels 6-9 (-14) mm long, subtended by a reddish or tan-colored accrescent bract 2-3.5 mm long, to 4.9 mm long in fruit, enclosing 2 smaller bracteoles; calyx 1.8-3 mm long (northern material with a blush of pink), lobes often dorsally pubescent, margins scarious and ciliate or glandular-ciliate; corolla 5.1-6(-7.2) mm long, the larger on rapidly developing, more open and elongated inflorescences, inner surface of tube smooth or sparsely pubescent below the middle; filaments 2.1-3 mm long, anthers about 1.5 mm long, spurs (1/2-)3/4-4/5 the length of the thecae. Ovary with up to 10 ovules per locule. Fruit more or less spherical, or slightly turbinate, 7.5-8.8(-9) mm diam, when ripe; seeds 4 or 5 per locule, 1.8-2.5 mm long. Chromosome number 2n = 26 (Callan, 1941).
Discussion:
The epithet xalapensis derives from the coastal city of the same name (Jalapa) located in eastern Mexico on the Gulf of Mexico. This seaport has been since the earliest days of European occupation an important commercial center.The uses of Arbutus have been described above (see under "Uses"). Perhaps the single most important use of A. xalapensis in today’s economy is for fuel wood, being burned either directly or after first having been converted to charcoal. I have found the wood of weathered chunks found in Eddy County, New Mexico, to be particularly suited for carving. The wood is dense [with a specific gravity of 0.75 (Sargent, 1893)], close-grained, and capable of being buffed to a satin gloss. It can be machined to rather close tolerances. The ripe fruit is edible though its use as a foodstuff must be regarded as negligible except in times of famine.Arbutus xalapensis is the most widespread (see Fig. 2) and most variable of the madrones. As treated here, the species consists of plants whose leaves are large and densely pubescent to plants with leaves small and more or less completely glabrous. In general, the larger and more consistently pubescentleaved plants are distributed in the southern reaches of the range while the glabrous and smaller-leaved plants make up the northernmost populations. The latter have in the past been recognized as A. texana or A. xalapensis var. texana. In intermediate areas- e.g., in southern Tamaulipas, Nuevo Leon, Coahuila, and Chihuahua-populations show intermediate leaf characteristics. The result is what appears to be a south to north cline involving a gradual change in diminishing leaf size and pubescence, with the hairs on the leaf surface becoming shorter and less dense. This trend is particularly apparent among the plants from the Sierra Madre Oriental and somewhat less so on those from the Sierra Madre Occidental. The critical transition region of morphs that unite the populations of the extremes lies approximately along the northern border of our coverage, the Tropic of Cancer.The bark surface-smooth versus rough, exfoliated versus retained- provides further variation within Arbutus xalapensis. The most prevalent condition is that the bark exfoliates early and more or less continuously until the plant reaches an advanced age, whereafter bark is retained beginning with the oldest parts near the base of the main axis or trunk. The area where bark is retained extends gradually upward until all the major axes of a very aged specimen may be covered by roughened bark. Occasionally, however, individuals begin to retain their bark fairly early, resulting in specimens that could be confused with the related A. tessellata, on which such bark retention is routine. In such circumstances, the two are best distinguished by their foliage, since the unusually long, glandular hairs of A. tessellata mark it as quite distinct from any other species. Moreover, the bark segments on the trunks and limbs differ qualitatively in the two species. Those of A. xalapensis are irregularly angled, only rarely somewhat symmetrical, while in A. tessellata they are nearly isodiametric plates about 3 cm long and two-thirds as wide. The color of the segments in both species is similar, being a light or dark gray caused by weathering.Just what brings about the cessation of bark exfoliation is not known. It may be due in part to a slowing down of the rate of growth in girth, but there may also be micro-environmental influences. Bark retention can occur on the undersides of main lateral branches even though this area of retention is not contiguous with the patches of retained bark at the base of the trunk. Similarly, bark can be retained on one side of the tree but not on the other. I have not been able to correlate such phenomena with direction of exposure nor with the proximity of other plants or physical features of the habitat. Thus, bark retention, as with almost every other vegetative feature of the plants, may simply be one of the characters that, while probably under some amount of genetic control, retains considerable phenotypic plasticity.There are two problems with the type specimens of Arbutus mollis and A. texana. The Humboldt Herbarium at P, available in microfiche edition (IDC 6209, fiches 78 & 79), lacks a specimen that would correspond to Kunth’s A. mollis. James Luteyn, while on a recent visit to P, located a sterile specimen {Humboldt & Bonpland 3983) that had been annotated by H. Sleumer as possibly the type of A. mollis. I have since examined this sheet and have compared it closely with Kunth’s original description and have concluded that it is not a type: the specimen belongs to A. tessellata. Furthermore, The original description of A. mollis, which includes mention of the flowers and inflorescence, applies very well to a soft-pubescent morph of A. xalapensis rather than to this specimen which has conspicuous glandular hairs. Indeed, Kunth clearly stated at the close of his diagnosis that the specimen at hand is "similar to the preceding," i.e., A. xalapensis. Lacking an authentic specimen with which to associate the name A. mollis, I have chosen to designate the description as the lectotype.Buckley (1862) wrote in the introduction to his article on the description of some new plants from Texas that "specimens of them are in the herbarium of the Academy of Natural Sciences at Philadelphia [PH], and also in the herbarium of Elias Durand, Esq." I have examined the type material of Arbutus at PH expecting to find a type of A. texana. The specimen so labeled, in Buckley’s hand, and noted as coming from the "type" locality is of Arctostaphylos uva-ursi, a species that, so far as is known, does not occur in Texas. A search was made of the holdings of Arctostaphylos and Arbutus at PH for additional Buckley specimens, on the chance that there had been a switch of labels, but none was found. Dr. Alicia Lourteig searched the herbarium of Elias Durand at P [see Chase (1936) for details on the transfer of Durand’s personal herbarium to Paris] and found a specimen of A. texana bearing a label in Buckley’s hand; this specimen has been designated the lectotype of A. texana.
The epithet xalapensis derives from the coastal city of the same name (Jalapa) located in eastern Mexico on the Gulf of Mexico. This seaport has been since the earliest days of European occupation an important commercial center.The uses of Arbutus have been described above (see under "Uses"). Perhaps the single most important use of A. xalapensis in today’s economy is for fuel wood, being burned either directly or after first having been converted to charcoal. I have found the wood of weathered chunks found in Eddy County, New Mexico, to be particularly suited for carving. The wood is dense [with a specific gravity of 0.75 (Sargent, 1893)], close-grained, and capable of being buffed to a satin gloss. It can be machined to rather close tolerances. The ripe fruit is edible though its use as a foodstuff must be regarded as negligible except in times of famine.Arbutus xalapensis is the most widespread (see Fig. 2) and most variable of the madrones. As treated here, the species consists of plants whose leaves are large and densely pubescent to plants with leaves small and more or less completely glabrous. In general, the larger and more consistently pubescentleaved plants are distributed in the southern reaches of the range while the glabrous and smaller-leaved plants make up the northernmost populations. The latter have in the past been recognized as A. texana or A. xalapensis var. texana. In intermediate areas- e.g., in southern Tamaulipas, Nuevo Leon, Coahuila, and Chihuahua-populations show intermediate leaf characteristics. The result is what appears to be a south to north cline involving a gradual change in diminishing leaf size and pubescence, with the hairs on the leaf surface becoming shorter and less dense. This trend is particularly apparent among the plants from the Sierra Madre Oriental and somewhat less so on those from the Sierra Madre Occidental. The critical transition region of morphs that unite the populations of the extremes lies approximately along the northern border of our coverage, the Tropic of Cancer.The bark surface-smooth versus rough, exfoliated versus retained- provides further variation within Arbutus xalapensis. The most prevalent condition is that the bark exfoliates early and more or less continuously until the plant reaches an advanced age, whereafter bark is retained beginning with the oldest parts near the base of the main axis or trunk. The area where bark is retained extends gradually upward until all the major axes of a very aged specimen may be covered by roughened bark. Occasionally, however, individuals begin to retain their bark fairly early, resulting in specimens that could be confused with the related A. tessellata, on which such bark retention is routine. In such circumstances, the two are best distinguished by their foliage, since the unusually long, glandular hairs of A. tessellata mark it as quite distinct from any other species. Moreover, the bark segments on the trunks and limbs differ qualitatively in the two species. Those of A. xalapensis are irregularly angled, only rarely somewhat symmetrical, while in A. tessellata they are nearly isodiametric plates about 3 cm long and two-thirds as wide. The color of the segments in both species is similar, being a light or dark gray caused by weathering.Just what brings about the cessation of bark exfoliation is not known. It may be due in part to a slowing down of the rate of growth in girth, but there may also be micro-environmental influences. Bark retention can occur on the undersides of main lateral branches even though this area of retention is not contiguous with the patches of retained bark at the base of the trunk. Similarly, bark can be retained on one side of the tree but not on the other. I have not been able to correlate such phenomena with direction of exposure nor with the proximity of other plants or physical features of the habitat. Thus, bark retention, as with almost every other vegetative feature of the plants, may simply be one of the characters that, while probably under some amount of genetic control, retains considerable phenotypic plasticity.There are two problems with the type specimens of Arbutus mollis and A. texana. The Humboldt Herbarium at P, available in microfiche edition (IDC 6209, fiches 78 & 79), lacks a specimen that would correspond to Kunth’s A. mollis. James Luteyn, while on a recent visit to P, located a sterile specimen {Humboldt & Bonpland 3983) that had been annotated by H. Sleumer as possibly the type of A. mollis. I have since examined this sheet and have compared it closely with Kunth’s original description and have concluded that it is not a type: the specimen belongs to A. tessellata. Furthermore, The original description of A. mollis, which includes mention of the flowers and inflorescence, applies very well to a soft-pubescent morph of A. xalapensis rather than to this specimen which has conspicuous glandular hairs. Indeed, Kunth clearly stated at the close of his diagnosis that the specimen at hand is "similar to the preceding," i.e., A. xalapensis. Lacking an authentic specimen with which to associate the name A. mollis, I have chosen to designate the description as the lectotype.Buckley (1862) wrote in the introduction to his article on the description of some new plants from Texas that "specimens of them are in the herbarium of the Academy of Natural Sciences at Philadelphia [PH], and also in the herbarium of Elias Durand, Esq." I have examined the type material of Arbutus at PH expecting to find a type of A. texana. The specimen so labeled, in Buckley’s hand, and noted as coming from the "type" locality is of Arctostaphylos uva-ursi, a species that, so far as is known, does not occur in Texas. A search was made of the holdings of Arctostaphylos and Arbutus at PH for additional Buckley specimens, on the chance that there had been a switch of labels, but none was found. Dr. Alicia Lourteig searched the herbarium of Elias Durand at P [see Chase (1936) for details on the transfer of Durand’s personal herbarium to Paris] and found a specimen of A. texana bearing a label in Buckley’s hand; this specimen has been designated the lectotype of A. texana.
Distribution and Ecology: Southern New Mexico and W Texas, U.S.A., south in mountainous topography through all the states of Mexico (except Campeche, Quintana Roo, Tabasco, and Yucatán), into Guatemala, Honduras, El Salvador, and Nicaragua, at elevations of (325-)2000-3000(-3400) m, at highest elevation in the Sierra Volcánica Transversal crossing southern Mexico. Flowering in Central America and southeastern Mexico November to mid-February, progressively later into April and May in the northernmost localities, rarely during mid-year. Fruiting follows after about six weeks.
Distribution:
Mexico North America| Chiapas Mexico North America| Distrito Federal Mexico North America| Durango Mexico North America| Guanajuato Mexico North America| Guerrero Mexico North America| Hidalgo Mexico North America| Jalisco Mexico North America| México Mexico North America| Michoacán Mexico North America| Morelos Mexico North America| Nayarit Mexico North America| Nuevo León Mexico North America| Oaxaca Mexico North America| Puebla Mexico North America| Querétaro Mexico North America| San Luis Potosí Mexico North America| Sinaloa Mexico North America| Sonora Mexico North America| Tamaulipas Mexico North America| Tlaxcala Mexico North America| Veracruz Mexico North America| Zacatecas Mexico North America| Guatemala Central America| Baja Verapaz Guatemala Central America| Chimaltenango Guatemala Central America| Guatemala Central America| Huehuetenango Guatemala Central America| Quezaltenango Guatemala Central America| Quiché Guatemala Central America| San Marcos Guatemala Central America| Sololá Guatemala Central America| Totonicapán Guatemala Central America| Zacapa Guatemala Central America| Honduras Central America| Comayagua Honduras Central America| Morazán El Salvador Central America| El Salvador Central America| Chalatenango El Salvador Central America| Santa Ana El Salvador Central America| Nicaragua Central America| Jinotega Nicaragua Central America| Madriz Nicaragua Central America| Matagalpa Nicaragua Central America| Nueva Segovia Nicaragua Central America|
Mexico North America| Chiapas Mexico North America| Distrito Federal Mexico North America| Durango Mexico North America| Guanajuato Mexico North America| Guerrero Mexico North America| Hidalgo Mexico North America| Jalisco Mexico North America| México Mexico North America| Michoacán Mexico North America| Morelos Mexico North America| Nayarit Mexico North America| Nuevo León Mexico North America| Oaxaca Mexico North America| Puebla Mexico North America| Querétaro Mexico North America| San Luis Potosí Mexico North America| Sinaloa Mexico North America| Sonora Mexico North America| Tamaulipas Mexico North America| Tlaxcala Mexico North America| Veracruz Mexico North America| Zacatecas Mexico North America| Guatemala Central America| Baja Verapaz Guatemala Central America| Chimaltenango Guatemala Central America| Guatemala Central America| Huehuetenango Guatemala Central America| Quezaltenango Guatemala Central America| Quiché Guatemala Central America| San Marcos Guatemala Central America| Sololá Guatemala Central America| Totonicapán Guatemala Central America| Zacapa Guatemala Central America| Honduras Central America| Comayagua Honduras Central America| Morazán El Salvador Central America| El Salvador Central America| Chalatenango El Salvador Central America| Santa Ana El Salvador Central America| Nicaragua Central America| Jinotega Nicaragua Central America| Madriz Nicaragua Central America| Matagalpa Nicaragua Central America| Nueva Segovia Nicaragua Central America|
Common Names:
madrone, madroño, madrona, madrón, encino roble, flora de pulca, guayavillo, Indio desnudo, kurúvasi, korúvasi, madroño colorado, nuzundu, pách-sich-ách-mixe, urúbasi, ya-hatzii
madrone, madroño, madrona, madrón, encino roble, flora de pulca, guayavillo, Indio desnudo, kurúvasi, korúvasi, madroño colorado, nuzundu, pách-sich-ách-mixe, urúbasi, ya-hatzii