Erythrostemon Klotzsch, in Link, Klotzsch & Otto, Icon. Pl. Rar. Horti. Berol. 2: 97, t. 39. 1844, descr. emended E. Gagnon & G. P. Lewis

Gagnon, Edeline, Bruneau, Anne, Hughes, Colin E., de Queiroz, Luciano Paganucci & Lewis, Gwilym P., 2016, A new generic system for the pantropical Caesalpinia group (Leguminosae), PhytoKeys 71, pp. 1-160 : 72-74

publication ID

https://dx.doi.org/10.3897/phytokeys.71.9203

persistent identifier

https://treatment.plazi.org/id/0B5638E5-F405-5247-B8DA-E0985B56872F

treatment provided by

PhytoKeys by Pensoft

scientific name

Erythrostemon Klotzsch, in Link, Klotzsch & Otto, Icon. Pl. Rar. Horti. Berol. 2: 97, t. 39. 1844, descr. emended E. Gagnon & G. P. Lewis
status

 

26 Erythrostemon Klotzsch, in Link, Klotzsch & Otto, Icon. Pl. Rar. Horti. Berol. 2: 97, t. 39. 1844, descr. emended E. Gagnon & G. P. Lewis Figs 41 View Figure 41 , 42 View Figure 42

Poincianella Britton & Rose (1930), pro parte, including the type species Caesalpinia mexicana A. Gray = Poincianella mexicana (A. Gray) Britton & Rose.

Schrammia Britton & Rose (1930).

Diagnosis.

Erythrostemon is closely related to Pomaria , but differs in habit, consisting of large shrubs and small to medium sized trees, or occasionally suffrutices (vs. shrubs, suffrutices, or perennial herbs in Pomaria ). It also differs by its ovate-lanceolate to orbicular sepals (vs. linear, laciniate sepals in Pomaria ), leaflets that are either eglandular or with conspicuous black sessile glands along the margin, these sometimes sunken in the sinuses of the crenulated margin (vs. leaflets with multiple glandular dots on the lower leaflet surfaces, that are orange in the field, drying black), the androecium and gynoecium free from the calyx (vs. the androecium and gynoecium cupped in the lower cucullate sepal), deflexed petals (vs. the two lower petals forming a horizontal platform above the lower cucullate sepal), and oblong-elliptic pods, the valves chartaceous to slightly woody, glabrous to pubescent, eglandular or with stipitate glands (vs. linear to sickle-shaped pods, the valves glabrous or with plumose trichomes and stipitate glands).

Type.

Erythrostemon gilliesii (Hook.) Klotzsch.

Emended description.

Shrubs or small to medium-sized trees varying from (0.5-) 1-12 (- 20) meters tall, occasionally suffrutices ( Erythrostemon nelsonii and Erythrostemon caudatus ), unarmed (except Erythrostemon glandulosus ); bark variable, smooth or rough, sometimes exfoliating, grey, greyish white, pale brown or reddish brown, often with white or black pustular lenticels; young stems terete (angular in Erythrostemon angulatus ), glabrous to densely pubescent, eglandular to densely covered in stipitate-glands. Stipules ovate-lanceolate, ovate to orbicular, apex acute to acuminate, caducous (persistent in Erythrostemon argentinus and Erythrostemon caudatus ). Leaves alternate, bipinnate, usually ending in a pair of pinnae plus a single terminal pinna; petioles (0.2-) 0.5-8 (- 10) cm long; rachis (0.5-) 1.2-14.5 (- 21.5) cm long, or lacking; petiole and rachis glabrous to densely pubescent, eglandular or covered in stipitate glands; pinnae in 1-6 (- 15) pairs, plus a terminal pinna (this occasionally lacking); leaflets in 2-13 (- 20) opposite pairs per pinna, size varying from a few mm in length and width (1.4-3 × 0.75-2 mm in Erythrostemon exilifolius ), to 5.3 × 2.5 cm, elliptic, oblong-elliptic, obovate, ovate or sub-orbicular, leaflet blades eglandular or with conspicuous black sessile glands along the margin, these sometimes sunken in the sinuses of the crenulated margin. Inflorescence an axillary or terminal raceme. Flowers bisexual, zygomorphic; calyx a short hypanthium with 5 sepals, 4.5-25 mm long, glabrous to pubescent, eglandular or with stipitate-glands, lower sepal cucullate in bud, all sepals caducous, the hypanthium persistent and abscising to form a free ring around the pedicel as the fruit matures; petals 5, free, imbricate, bright golden yellow, to creamish yellow, salmon pink or pink-scarlet, the median petal often with red-orange markings, the corolla diverse in form, the median petal 6-32 × 3.2-20 mm, the lateral petals 6-32 × 3.5-18.5 mm, petal blades eglandular or the dorsal surface covered with stipitate glands, claw margins glabrous to pubescent, eglandular or with gland-tipped trichomes; stamens 10, free, 0.6-3.5 cm long (up to 10 cm in Erythrostemon gilliesii ), filaments pubescent, eglandular or with stipitate glands; ovary pubescent, eglandular or with sessile or stipitate glands, stigma a terminal fringed chamber. Fruit a chartaceous to coriaceous or slightly woody, laterally compressed pod, with a marcescent style persisting as a small beak, elastically dehiscent with twisting valves, 2.4-12.5 × 1-2.8 cm, glabrous to pubescent, eglandular or with stipitate glands, (1-) 2-7 (- 8)-seeded. Seeds yellow to ochre-brown, or mottled with grey and black.

Geographic distribution.

The genus comprises 34 taxa in 31 species. Its circumscription is emended here to include many species previously placed in Central American and Mexican Poincianella . 22 species are found across the southern USA, Mexico and Central America, one occurs in the Caribbean (Cuba and Hispaniola), eight occur in South America, with one endemic in the caatinga vegetation of Brazil, and the other seven in Argentina, Bolivia, Chile, and Paraguay.

Habitat.

Low-elevation seasonally dry tropical forests across Mexico, Central America, the Caribbean and in caatinga vegetation in Brazil; also in patches of dry forest, deserts, yungas-puna transition zones, and chaco-transition forests in Argentina, Bolivia, Chile and Paraguay.

Etymology.

From erythro - (Greek: red) and stemon (Greek: stamen), the type species Erythrostemon gilliesii (Wall. ex Hook.) Klotzsch has long red exserted stamens, but this is unusual in the genus as circumscribed here.

Notes.

Species descriptions (under Caesalpinia binomials) are available in Lewis (1998). A key is also available in that revision, but it includes species now considered to belong in Cenostigma , Arquita , and Hoffmannseggia .

References.

Britton and Rose (1930); Burkart (1936: 82-84, 97-108); Ulibarri (1996); Lewis (1998); De Queiroz (2009: 120-121).

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Fabales

Family

Leguminosae

Loc

Erythrostemon Klotzsch, in Link, Klotzsch & Otto, Icon. Pl. Rar. Horti. Berol. 2: 97, t. 39. 1844, descr. emended E. Gagnon & G. P. Lewis

Gagnon, Edeline, Bruneau, Anne, Hughes, Colin E., de Queiroz, Luciano Paganucci & Lewis, Gwilym P. 2016
2016
Loc

Poincianella

Britton & J.N.Rose 1930
1930