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Mariosousa salazarii - habit
Mariosousa salazarii
Mariosousa salazarii - seeds
Mariosousa salazarii
Mariosousa salazarii - bark
Mariosousa salazarii - bark
Mariosousa salazarii - habitat
Mariosousa salazarii - flowers
Mariosousa salazarii - habit
Mariosousa salazarii
Mariosousa salazarii
Mariosousa salazarii - habit
Mariosousa salazarii
Mariosousa salazarii - flowers
Mariosousa salazarii
Mariosousa salazarii
Mariosousa salazarii
Mariosousa salazarii
Mariosousa salazarii
Mariosousa salazarii - habit

Name

Mariosousa salazarii (Britton & Rose) Seigler & Ebinger, comb. nov. 

Synonymy and types

Acacia salazari (Britton & Rose) Lundell, Contr. Univ. Michigan Herb. 4:8. 1940. - Senegalia salazari Britton & Rose, N. Amer. Fl. 23:113. 1928. - TYPE: Mexico, Michoacan, Xochiapa, 13 April 1912, F.Salazar s.n. (holotype: US!, isotypes: MEXU!, NY!).

Formal description

Tree to 15 m tall. Bark yellow to red or light gray, exfoliating and papery.  Twigs greenish brown to light reddish brown, not flexuous, usually glabrous.  Short shoots absent.  Leaves alternate, 50-180 mm long. Stipules herbaceous, light brown, narrowly linear, to 4.5 x 0.6 mm near the base, glabrous, persistent.  Petiole adaxially grooved, 20-50(60) mm long, mostly glabrous; petiole gland solitary, located between the lower pinna pair, sessile, nearly circular, 0.5-1.3 mm across, globose to doughnut-shaped, absent on most leaves.  Rachis adaxially grooved, 35-140 mm long, glabrous to lightly puberulent, a sessile, doughnut- to saucer-shaped gland, 0.5-1.0 mm across, between the pinnae of the upper 1 to 2(3) pinna pairs.  Pinnae 7 to 18 pairs per leaf, 35-63 mm long, 4-12 mm between pinna pairs.  Petiolules 2.4-4.0 mm long..  Leaflets 20 to 38 per pinna, opposite, 0.8-1.5 mm between leaflets, linear, 2.5-6.4 x 0.9-1.3 mm, usually lightly pubescent with appressed hairs beneath, commonly light greenish-purple and glabrous above, lateral veins usually not obvious, only 1 or rarely 2 veins from the base, base oblique, margins usually ciliate, apex narrowly acute to acuminate.  Inflorescence a loosely flowered, cylindrical spike 45-110 mm long, 1 to 3 from the leaf axil, or rarely in terminal racemose clusters. Peduncle 5-10 x 0.5-1.0 mm, lightly puberulent.   Involucre absent.  Floral bracts linear, to 1 mm long, puberulent, early deciduous.  Flowers sessile, creamy-white; calyx 5-lobed, 1.5-2.3 mm long, lightly appressed pubescent; corolla 5-lobed, 2.5-3.5 mm long, lightly appressed pubescent; stamen filaments 4.5-7.0 mm long, distinct; ovary glabrous, on a stipe to 0.3 mm long.  Legumes yellowish brown, straight, flattened, not constricted between the seeds, oblong, 115-180 x 21-35 mm, cartilagious, transversely striate, glabrous, eglandular, dehiscent along both sutures; stipe to 13 mm long; apex obtuse.  Seeds uniseriate, no pulp, dark reddish brown, circular to oblong, strongly flattened, 10.0-14.5 x 7-12 mm, smooth; pleurogram U-shaped, 1.2-3.0 mm across.   Flowers: April-June.  Chromosome number: Not determined.

Distribution

Thorn-scrub thickets, and disturbed dry forests from near sea level to 1800 m (but mostly above 1000 m) elevation in the states of Guererro, México, Michoacán, Morelos, Oaxaca and Puebla, Mexico.

Additional info

A small tree, rarely more than 10 m tall, Mariosousa salazari is restricted to dry habitats, particularly thorn -scrub forests of southern Mexico.  Many collections are from above 1000 m elevation, but a few individuals are reported from near sea level.  Mariosousa salazari is similar to M. acatlensis with which it is sympatric nearly throughout its entire range.  Both have leaves with many pinna pairs, and leaflets of similar size that are lightly pubescent with appressed hairs beneath and commonly light greenish-purple and glabrous above.  Mariosousa acatlensis, however, has minute purple glands along the petiole, rachis, and at the base of most leaflets; pinnae with more than 36 pairs of leaflets; petiolules that are most less than 2.0 mm long; and dark gray, fissured bark.  Mariosousa salazari, in contrast, lacks the small purple gland, usually has fewer than 38 pairs of leaflets per pinna, petiolules that usually exceed 2.5 mm in length, and yellow to reddish bark that is papery and exfoliating.  Some specimens with a mixture of characteristics of these two species suggest that they probably hybridize in Guerrero.  Determination must await field studies.

Although Mariosousa salazari is similar to other species of this group from southern Mexico, particularly M. centralis and M. usumacintensis, the papery, exfoliating bark allows for easy separation.  Also, both of these species have pinnae with more than (36)40 leaflet pairs, whereas M. salazari has 38 or fewer leaflet pairs per pinnae.  Mariosousa usumacintensis has large, flattened petiolar glands that are located on the lower half of the petiole, while M. salazari commonly lacks petiolar glands.  Occasionally, petiolar glands are found on a few leaves of some specimens; these are globose to doughnut-shaped, and located between the lower pair of pinnae.  These glands are not common; most specimens lack petiolar glands altogether.  On the remaining specimens, only one or two of the leaves have petiolar glands, and many are globose, not doughnut-shaped as is typical in most taxa of this group.  Mariosousa salazari and M. millefolia are the only taxa in this group that usually lack petiolar glands.

Flowering time

April-June.

Representative specimens

MEXICO:

Guerrero:

México:

Michoacán:

Morelos:

Oaxaca:

Puebla:

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