Holocalyx

Taxonomy

Holocalyx M. Micheli Mém. Soc. Phys. Genève 28(7): 41. 1883.

Subfamily: Faboideae.
Phylogenetic Number: 3.1.12.
Tribe: Swartzieae.
Group: Lecointea.
Species Studied - Species in Genus: 1 studied; 1 in genus.

Description

Fruit: A legume (breaking between seed chambers into "articles"), or a nutlet; unilocular; 1.4–2.2 cm long; 1.2–1.7 cm wide; 1.2–2.7 cm thick; length less than twice as long as width; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical; ovate to circular; inflated; terete; without beak, or with beak; straight; with solid beak the same color and texture as fruit; rounded at apex; aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; fleshy (in literature), or ligneous (drying); margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate, or nonstipitate; with the stipe 0.1–2 mm long; indehiscent. Replum invisible. Epicarp dull; monochrome; brown (when dry, dark), or yellow (when ripe in life); with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; not veined; not tuberculate; wrinkled (when dry); not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 1-layered; without balsamic vesicles; without reniform canals; when dry solid, or fleshy (in life); ligneous (when dry). Endocarp present; visible; dull; opaque; monochrome; black; scurfy; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1. Aril absent.

Seed: 8.9–16 mm long; 8–15 mm wide; 7–13 mm thick; not overgrown; not angular; symmetrical; circular; terete; with surface wrinkled; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp, or partially adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; monochrome; brown; glabrous; smooth; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from hilum to near base of seed and terminating; not bifurcating; darker than testa; darker brown; flush. Hilum present; partially concealed; concealed by funicular remnant; without faboid split; larger than punctiform; ca. 4 mm long; with straight outline; narrowly oblong; subapical to radicle tip; flush; not within corona, halo, or rim. Lens discernible; ca. 3 mm long; with margins straight; linear; not in groove of raphe; adjacent to hilum; ca. 3 mm from hilum; flush; same color as testa; brown; not within corona, halo, or rim. Endosperm absent. Cotyledons not smooth; 5–7-branched grooves (from veins of testa) on each face; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; completely concealing radicle; entire over radicle; without lobes; without margins recessed; yellow, or brown; inner face flat; glabrous on inner face. Radicle not differentiated from cotyledon.

Distribution

Southeastern Brazil, Paraguay, and northeastern Argentina.

New World; South America; Argentina and Brazil.

Generic Notes

Polhill (1994a, 1994b) transferred this genus from the Sophoreae (2) following Herendeen's (1995) cladistic analysis. The cotyledons are fused along their edges for more than half of their length starting from the region of the embryanic axis. The embryanic axis is poorly developed only consisting of an area of differentiating cells. Harendeen (1994) proposed that Holocalyx belongs to a clade also including Lecointea (1.08), Harleyodendron (1.09), Exostyles (1.10), and Zollernia (1.11) and that Holocalyx is most closely related to Lecointea. Its rudimentary embryo and fused cotyledons are similar to those of L. amazonica and L. tango, respectively, which supports Herendeen's hypothesis.

Tribal Notes

Tribe Swartzieae

Swartzieae has been assigned to Caesalpinioideae (Cowan, 1968), Swartzioideae (de Candolle, 1825a, 1825b; Corner, 1976), and Faboideae (Bentham, 1865, Hutchinson, 1964, Cowan, 1981). In 1968, Cowan (1968) was unable "finally to resolve the sub-familial relationship of Swartzia," but in 1981, he (Cowan 1981) placed it in the Faboideae and stated, "... features appear to support the arrangement adopted here (Cowan 1981) with the Swartzieae representing a relatively less-advanced position in the Papilionoideae (Faboideae). This conclusion is now supported by wood anatomy ..., by nodulation proclivity ..., and by chemistry ...; chromosome numbers of n=8, 10 or 14 ..., as well as pollen morphology ..., do not negate this conclusion." In the most recent assessment of the Fabaceae, Polhill (1994a, 1994b) maintained Swartzieae as a basal tribe of Faboideae, "transitional to the Caesalpinioideae." He transferred four genera from Sophoreae (2) into the Swartzieae, Amburana (3.1.15), Ateleia (3.1.13), Cyathostegia (3.1.14), and Holocalyx (3.1.12), and arranged the genera in four groups corresponding to clades in Herendeen's (1994) cladistic analysis. Herendeen carried out cladistic analyses using morphological characters of all Swartzieae genera, 19 genera of Sophoreae, and three Caesalpinioideae genera. He concluded that Swartzieae is polyphyletic and that it should be disbanded and its genera transferred to Sophoreae. Preliminary rbcL data (Doyle et al. 1997) supported his conclusions. Ireland et al. (2000) also carried out molecular phylogenetic studies. They also concluded that Swartizeae is polyphyletic, and suggested that possibly tribe Swartzieae could be maintained with Swartzia (3.1.01), Bobgunnia (3.1.01A), Bocoa (3.1.02), Ateleia (3.1.13), Cyathostegia (3.1.14) and the current remaining Swartzieae genera transferred to other tribes. Our seed data neither support nor refute the overall outlines of Herendeen's cladograms; they are discussed below for a few genera. Ferguson and Skvarla (1991) reported on the pollen morphology of Aldina and Swartzia (1.01), and the nine other genera of Swartzieae are covered in Ferguson and Skvarla (1988). Their data are summarized in a computer-generated key in Vezey et al. (1991). The pollen data for the tribe should be compared with our seed-fruit morphological data.