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
Description:
Species Description - Tree, 2-9(-15) m tall; bark dark gray, rough, the checkered plates persisting on even the smallest branchlets, except those actively elongating. Leaves dark green and glossy-glabrous or fleetingly puberulent above, lighter green and pubescent beneath, the hairs concentrated near the base of the blade and along the mid vein; blades broadly ovate to elliptic, 8-15 × 6-9 cm; base rounded or subcordate; apex obtuse or sometimes acute; margins smooth or rarely irregularly finely serrate; petioles pubescent with white or tan hairs, 2-3 cm long. Inflorescence a cluster of racemes, often congested, terminal on main shoots, or more often terminal on lateral shoots; axes (including pedicels) usually glandular-pubescent, the hairs 0.2-0.3(-0.7) mm long. Flowers erect or nearly so on accrescent pedicels to 1 cm long in fruit, subtended by a scale-like bract 3.5-5 mm long, enclosing two smaller bracteoles; calyx pale or yellow-green, all but the deltoid lobes hidden beneath the inflated corolla base; corolla creamy white or greenish-white, (4-)5.2-7.5 mm long, urceolate, developing a prominent circumferential dimple at about midway its length; anthers 1.5-1.7 mm long; ovary 5-locular with several ovules per locule. Fruit ripening to a blackish-red; more or less spherical, to 1.2 cm diam.; seeds 2-2.8 mm long.
Species Description - Tree, 2-9(-15) m tall; bark dark gray, rough, the checkered plates persisting on even the smallest branchlets, except those actively elongating. Leaves dark green and glossy-glabrous or fleetingly puberulent above, lighter green and pubescent beneath, the hairs concentrated near the base of the blade and along the mid vein; blades broadly ovate to elliptic, 8-15 × 6-9 cm; base rounded or subcordate; apex obtuse or sometimes acute; margins smooth or rarely irregularly finely serrate; petioles pubescent with white or tan hairs, 2-3 cm long. Inflorescence a cluster of racemes, often congested, terminal on main shoots, or more often terminal on lateral shoots; axes (including pedicels) usually glandular-pubescent, the hairs 0.2-0.3(-0.7) mm long. Flowers erect or nearly so on accrescent pedicels to 1 cm long in fruit, subtended by a scale-like bract 3.5-5 mm long, enclosing two smaller bracteoles; calyx pale or yellow-green, all but the deltoid lobes hidden beneath the inflated corolla base; corolla creamy white or greenish-white, (4-)5.2-7.5 mm long, urceolate, developing a prominent circumferential dimple at about midway its length; anthers 1.5-1.7 mm long; ovary 5-locular with several ovules per locule. Fruit ripening to a blackish-red; more or less spherical, to 1.2 cm diam.; seeds 2-2.8 mm long.
Discussion:
With the addition of Arbutus madrensis, there are now three species in western Mexico that have the characteristic of retaining their bark. The other two are A. tessellata and A. arizonica. All three, however, are easily distinguished by their leaves (see Key to the Species).Arbutus madrensis will become a more familiar species as a consequence of new logger roads that have been built into remote and difficult terrain of Durango and its neighboring states in Mexico. In the forests of northern Durango, this newly described madrone is sometimes the dominant species in the pine and oak zone (S. González-E., pers. comm.).
With the addition of Arbutus madrensis, there are now three species in western Mexico that have the characteristic of retaining their bark. The other two are A. tessellata and A. arizonica. All three, however, are easily distinguished by their leaves (see Key to the Species).Arbutus madrensis will become a more familiar species as a consequence of new logger roads that have been built into remote and difficult terrain of Durango and its neighboring states in Mexico. In the forests of northern Durango, this newly described madrone is sometimes the dominant species in the pine and oak zone (S. González-E., pers. comm.).
Distribution:
Mexico North America| Durango Mexico North America|
Mexico North America| Durango Mexico North America|