Alantsilodendron Villiers, Bull. Mus. Natl. Hist. Nat., B, Adansonia 16: 65. 1994.

Bruneau, Anne, de Queiroz, Luciano Paganucci, Ringelberg, Jens J., Borges, Leonardo M., Bortoluzzi, Roseli Lopes da Costa, Brown, Gillian K., Cardoso, Domingos B. O. S., Clark, Ruth P., Conceicao, Adilva de Souza, Cota, Matheus Martins Teixeira, Demeulenaere, Else, de Stefano, Rodrigo Duno, Ebinger, John E., Ferm, Julia, Fonseca-Cortes, Andres, Gagnon, Edeline, Grether, Rosaura, Guerra, Ethiene, Haston, Elspeth, Herendeen, Patrick S., Hernandez, Hector M., Hopkins, Helen C. F., Huamantupa-Chuquimaco, Isau, Hughes, Colin E., Ickert-Bond, Stefanie M., Iganci, Joao, Koenen, Erik J. M., Lewis, Gwilym P., de Lima, Haroldo Cavalcante, de Lima, Alexandre Gibau, Luckow, Melissa, Marazzi, Brigitte, Maslin, Bruce R., Morales, Matias, Morim, Marli Pires, Murphy, Daniel J., O'Donnell, Shawn A., Oliveira, Filipe Gomes, Oliveira, Ana Carla da Silva, Rando, Juliana Gastaldello, Ribeiro, Petala Gomes, Ribeiro, Carolina Lima, Santos, Felipe da Silva, Seigler, David S., da Silva, Guilherme Sousa, Simon, Marcelo F., Soares, Marcos Vinicius Batista & Terra, Vanessa, 2024, Advances in Legume Systematics 14. Classification of Caesalpinioideae. Part 2: Higher-level classification, PhytoKeys 240, pp. 1-552 : 1

Alantsilodendron Villiers, Bull. Mus. Natl. Hist. Nat., B, Adansonia 16: 65. 1994.

Figs 144 , 145 , 146 , 160

Type.

Alantsilodendron villosum (R. Vig.) Villiers [≡ Dichrostachys villosa R. Vig.]

Description.

Unarmed (weak thorns in one species) shrubs or small treelets (Fig. 144L ), 1-5 m, much-branched from base, branches often plagiotropic; brachyblasts present, usually clothed in distichous or spirally arranged rows of persistent or caducous stipule bases. Stipules monomorphic, striate, ovate. Leaves bipinnate, extrafloral nectary between lower pair, and sometimes more distal pinnae; pinnae 1-7 pairs (10-50 in one species); leaflets 2-20 pairs per pinna (30-50 in one species), linear to ovate, base truncate. Inflorescence usually a capitulum (Fig. 145I ), occasionally a condensed spike, usually solitary in leaf axils of new growth or more often on short shoots, flowers usually lacking a pseudopedicel; bracteoles subtending individual flowers carinate, 1-nerved; inflorescence composed usually entirely of hermaphrodite flowers but some species with sterile flowers proximally, fertile flowers distally, and often a few functionally staminate flowers in between. Flowers with sepals and petals valvate in bud; sterile flowers with a 5-lobed or entire calyx, fused ½-¾ its length, each lobe with a central raised nerve; petals 5, connate, each petal 1-3 nerved, staminodia 10, filamentous, white; functionally staminate flowers similar to fertile ones but either lacking an ovary or having only a rudimentary one; bisexual flowers similar to sterile ones but larger, with a 5-lobed calyx and 5 connate petals (free in one species), usually linear or lanceolate, 1-3 nerved; stamens 8-10, filaments exserted at anthesis, anthers either with a terminal apiculum or lacking an apical gland; pollen of 8- or 16-grained calymmate or acalymmate polyads, grains shed as tetrads if acalymmate, exine verrucate or psilate; ovary ovate, sessile, densely pilose or pubescent, style exserted (rarely included) at anthesis, stigma porate to broad funnelform. Fruits sessile, terete when immature, dorsiventrally compressed at maturity, either inertly dehiscent or more often elastically dehiscent from the apex, the valves recurved but not coiling after dehiscence (Fig. 146Q ), pericarp woody in elastically dehiscent species, coriaceous in inertly dehiscent ones, sutural ribs often greatly thickened, interior of pod usually invaginated between seeds. Seeds obliquely or laterally positioned in the fruit, ovate to rhomboidal, pleurogram either U-shaped or forming nearly a complete oval.

Chromosome number.

Unknown.

Included species and geographic distribution.

Eleven species, in southern, western, and far northern Madagascar (Fig. 160 ).

Ecology.

Restricted to seasonal xerophytic deciduous woodlands and scrub, especially in the spiny forests of south-western Madagascar, deciduous in long dry season.

Etymology.

From alantsili -, the Madagascan name for dry forest, and - dendron (Greek = tree) in reference to the distribution of the genus restricted to dry forest.

Human uses.

Unknown.

Notes.

Alantsilodendron is closely related to Dichrostachys and Gagnebina (Fig. 143 ) but differs in having fused petals, and typically a capitate inflorescence lacking staminodial flowers. The current non-monophyly of Alantsilodendron (Fig. 143 ) will be dealt with in a forthcoming monograph (see Dichrostachys and Dichrostachys clade notes for more details).

Taxonomic references.

Villiers (1994, 2002), both including illustrations.

Figures

Figure 143. Generic relationships in the Dichrostachys clade (tribe Mimoseae). Note that the non-monophyly of Dichrostachys and Alantsilodendron has been simplified in this figure (see Suppl. material 2). For description of phylogeny and support values, see Fig. 6 caption (page 63).

Figure 144. Habit and growth forms of genera of the Dichrostachys clade A herbaceous to weakly woody thicket of shrubby Neptunia plena (L.) Benth. in seasonally inundated ruderal habitat, Bolivia (Saerkinen 2159) B, C medium-sized to large trees of Lemurodendron capuronii Villiers & P. Guinet, north-western Madagascar (Koenen 429) D small tree of Leucaena matudae (Zarate) C. E. Hughes in seasonally dry tropical forest, Guerrero, Mexico (Hughes 2153) E shrub of Kanaloa kahoolawensis Lorence & K. R. Wood cultivated, National Tropical Botanical Garden, Kaua'i, Hawaii F small treelet of Desmanthus fruticosus Rose, Baja California, Mexico (Hughes 1532) G prostrate woody suffrutex of Desmanthus acuminatus Benth., Potosi, Bolivia (Hughes 2314) H shrub of Mimozyganthus carinatus (Griseb.) Burkart, Santa Cruz, Bolivia (Hughes 2476) I shrub of Prosopidastrum globosum (Gillies ex Hook. & Arn.) Burkart, Mendoza, Argentina J shrublet of Calliandropsis nervosa (Britton & Rose) H. M. Hern. & P. Guinet, Puebla, Mexico (Hughes 1784) K small treelet of Dichrostachys cinerea (L.) Wight & Arn., Kruger National Park, South Africa L small treelet of Alantsilodendron pilosum Villiers, S. Madagascar (Luckow 4162) M treelet of Gagnebina pterocarpa (Lam.) Baill., Madagascar N shrub of Dichrostachys venosa Villiers, in dry spiny forest, southern Madagascar. Photo credits A, D-H, J CE Hughes B, C E Koenen I Estepa Patagonica K B Dupont L M Luckow M C Commenge naturetropicale N D Du Puy.

Figure 145. Inflorescences and flowers of genera of the Dichrostachys clade A Lemurodendron capuronii Villiers & P. Guinet (Koenen 435) B inflorescence of Neptunia plena (L.) Benth., basal flowers sterile with showy yellow petaloid staminodia (Wood 26650) C inflorescence of Leucaena esculenta (Sesse & Mocino ex DC.) Benth. (Hughes 1326) D inflorescences and tergeminate leaves of Kanaloa kahoolawensis Lorence & K. R. Wood E fascicles of capitate inflorescences in axils of coevally developing leaves, Schleinitzia fosbergii Nevling & Niezgoda F inflorescences of Desmanthus bicornutus S. Watson showing basal sterile flowers with exserted white showy staminodia (Hughes 1526) G capitate inflorescences of Prosopidastrum globosum (Gillies ex Hook. & Arn.) Burkart H semi-spherical capitate inflorescences of Calliandropsis nervosa (Britton & Rose) H. M. Hern. & P. Guinet (Hughes 1784) I inflorescence of Alantsilodendron ramosum Villiers J spicate inflorescences of Gagnebina pterocarpa (Lam.) Baill., the basal flowers sterile with showy white staminodia K spicate inflorescence of Dichrostachys cinerea (L.) Wight & Arn., basal flowers sterile with showy pink staminodia L compact spikes of Dichrostachys akataensis Villiers the basal flowers sterile with showy pale pink staminodia. Photo credits A E Koenen B, C, F, H, J, K CE Hughes D A Palomino E Lauren Gutierrez G D Cabral, Flora Mondocina I, L D Du Puy.

Figure 146. Fruits of genera of the Dichrostachys clade A leaves and pod of Lemurodendron capuronii Villiers & P. Guinet, north-eastern Madagascar (Koenen 429) B Neptunia plena (L.) Benth. fruits dehiscing along the dorsal suture (Wood 26650) C ripe pods of Leucaena cruziana Britton & Rose, Oaxaca, Mexico (Hughes 1300) D cluster of unripe pods on a single inflorescence of Leucaena leucocephala (Lam.) de Wit subsp. glabrata (Rose) S. Zarate, Honduras (Hughes 1557) E ripe pods of Desmanthus leptophyllus Kunth dehiscing along both sutures (Hughes 3098) F unripe fruit of Mezcala balsensis (J. L. Contr.) C. E. Hughes & J. L. Contr., held erect, Guerrero, Mexico G ripe fruits of Mezcala balsensis dehiscing from the apex along both sutures H, I unripe and ripe fruits of Kanaloa kahoolawensis Lorence & K. R. Wood, cultivated at the Olinda rare plant propagation facility, Maui, Hawaii, USA J ripe fruits of Schleinitzia insularum (Guilemin) Burkart, the valves tardily splitting along both sutures but indehiscent K winged fruits of Gagnebina pterocarpa (Lam.) Baill., Madagascar L unripe, lomentiform fruits of Prosopidastrum globosum (Gillies ex Hook. & Arn.) Burkart which break up into one- or few-seeded fragments when ripe M ripe fruits of Mimozyganthus carinatus (Griseb.) Burkart, S Bolivia (Hughes 2476) N ripe fruits, elastically dehisced from the apex, Calliandropsis nervosa (Britton & Rose) H. M. Hern. & P. Guinet, Puebla, Mexico (Hughes 1784) O unripe coiled fruits of Dichrostachys cinerea (L.) Wight & Arn. P ripe fruits dehiscing elastically from the apex, Dichrostachys venosa Villiers, southern Madagascar Q ripe fruits of Alantsilodendron pilosum Villiers, Madagascar. Photo credits A E Koenen B-E, M, N C Hughes F, G J Luis Contreras H, I A Palomino J G McCormack, Cook Islands Biodiversity K, P, Q D Du Puy L I Specogno, Flora Mendocina O Atamari (CC-BY-SA- 3.0).

Figure 160. Distribution of Alantsilodendron based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.