Platanus wrightii

Platanus wrightii (S. Wats)

by Perry Crampton, Native Plants Class 2003
Common names: Arizona sycamore, Buttonwood, Solar tree, Alamo tree
Family: Platanaceae
Synonymy: Platanus racemosa Nutt. var wrightii (S. Wats.) L. Benson (1).
Etymology: From the Greek platys, meaning broad and flat, referring to the leaves and wrightii, possibly named after British botanist William Wright. (2,6).

Identification
Growth form: Platanus wrightii is a slow growing tree attaining a height of 24.5 meters when mature typically branching near the base with one large limb often extended over a water source. The crown is open and spreading (4).
Roots: N/A
Stems: Moderately short stems with a zig zag shape, orange-brown and green, fuzzy when young, circular leaf scar surrounds the reddish cone-shaped bud covered with a single cap-like scale (4).
Leaves: Leaves are simple and alternate with occasionally persistent stipules and flaring margins entire to serrate. The leaf blade is palmately 3-7 lobed, base is truncate, cordate, or cuneate; surfaces are tomentose or glabrescent (3). Leaves are green above and paler and fuzzy below (4).
Inflorescences/flowers: Platanus wrightii inflorescences are axillary, solitary, appearing with the leaves. Staminate inflorescences have 1-5 heads that are green, sessile and globose. Pistillate inflorescences have 1-7 heads, terminal (sometimes lateral), sessile or pedunculate, globose, the whole much elongate and pendulous in fruit (3).
Fruit: Achenes mature in the fall, often persisting until spring and are tan, club-shaped, quadrangular, with terminal stylar beak, surrounded by numerous hairs. Hairs are basally attached, thin, unbranched, 2/3 to nearly equal to length of achene (3).
Similar species: P. acerifolia (London Plane Tree) & var. pyramidalis; P. occidentalis (American Plane Tree); P. orientalis (Oriental Plane Tree); P. cuneata; P. racemosa (California Plane Tree) (5).

Ecology
Life history: Perennial
Native/introduced: Native
Photosynthetic pathway: C3
Phenology: Blooms in spring, fruits all summer with male green marbles 1.3 cm in diameter and female green spiky balls 3.8 cm in diameter. Balls disintegrate over winter dispersing the seeds with the wind in spring (4).
Distribution: Platanus wrightii has a constricted range, growing in southwest New Mexico, southern and central Arizona and northern Mexico (2).

Uses: The wood of the buttonwood is difficult to work and therefore has limited commercial value; its resistance to splitting makes it useful for butcher blocks and buttons (3).

References
1. http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=PLWR2&mode

2. http://ww.treeguide.com/Species.asp?SpeciesID=756

3. http://flora.huh.harvard.edu.8080/flora/browse.do?flora_id=1&taxon_id=10703

4. http://www.cnr.vt.edu/dendro/dendrology/Syllabus2/pwrightii.htm

5. http://www.botany.com/platanus.html

6. Quattrocchi, Umberto. CRC World Dictionary of Plant Names, Vol. IV. CRC Press, London, UK

Platanus wrightii (S. Wats) by Perry Crampton, Native Plants Class 2003 Common names: Arizona sycamore, Buttonwood, Solar tree, Alamo tree Family: Platanaceae Synonymy: Platanus racemosa Nutt. var wrightii (S. Wats.) L. Benson (1). Etymology: From the Greek platys, meaning broad and flat, referring to the leaves and wrightii, possibly named after British botanist William Wright. (2,6). Identification Growth form: Platanus wrightii is a slow growing tree attaining a height of 24.5 meters when mature typically branching near the base with one large limb often extended over a water source. The crown is open and spreading (4). Roots: N/A Stems: Moderately short stems with a zig zag shape, orange-brown and green, fuzzy when young, circular leaf scar surrounds the reddish cone-shaped bud covered with a single cap-like scale (4). Leaves: Leaves are simple and alternate with occasionally persistent stipules and flaring margins entire to serrate. The leaf blade is palmately 3-7 lobed, base is truncate, cordate, or cuneate; surfaces are tomentose or glabrescent (3). Leaves are green above and paler and fuzzy below (4). Inflorescences/flowers: Platanus wrightii inflorescences are axillary, solitary, appearing with the leaves. Staminate inflorescences have 1-5 heads that are green, sessile and globose. Pistillate inflorescences have 1-7 heads, terminal (sometimes lateral), sessile or pedunculate, globose, the whole much elongate and pendulous in fruit (3). Fruit: Achenes mature in the fall, often persisting until spring and are tan, club-shaped, quadrangular, with terminal stylar beak, surrounded by numerous hairs. Hairs are basally attached, thin, unbranched, 2/3 to nearly equal to length of achene (3). Similar species: P. acerifolia (London Plane Tree) & var. pyramidalis; P. occidentalis (American Plane Tree); P. orientalis (Oriental Plane Tree); P. cuneata; P. racemosa (California Plane Tree) (5). Ecology Life history: Perennial Native/introduced: Native Photosynthetic pathway: C3 Phenology: Blooms in spring, fruits all summer with male green marbles 1.3 cm in diameter and female green spiky balls 3.8 cm in diameter. Balls disintegrate over winter dispersing the seeds with the wind in spring (4). Distribution: Platanus wrightii has a constricted range, growing in southwest New Mexico, southern and central Arizona and northern Mexico (2). Uses: The wood of the buttonwood is difficult to work and therefore has limited commercial value; its resistance to splitting makes it useful for butcher blocks and buttons (3). References 1. http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=PLWR2&mode 2. http://ww.treeguide.com/Species.asp?SpeciesID=756 3. http://flora.huh.harvard.edu.8080/flora/browse.do?flora_id=1&taxon_id=10703 4. http://www.cnr.vt.edu/dendro/dendrology/Syllabus2/pwrightii.htm 5. http://www.botany.com/platanus.html 6. Quattrocchi, Umberto. CRC World Dictionary of Plant Names, Vol. IV. CRC Press, London, UK