Rapateaceae

Taxonomy

Family name: Rapateaceae Dumortier

Synonym(s): [none]

Common name(s): rapatea family

*Number of genera/species: 16/94

List of genera records in GRIN-Global

Disseminule

seed

Description

Fruit dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
, septicidalsepticidal:
type of capsular dehiscence, opening longitudinally by separating between the septa of adjacent carpels
capsulecapsule:
a dry, dehiscent fruit formed by two or more carpels
, 3–10 mm long, ovateovate:
2D shape—egg-shaped in outline, widest point is towards one end of the organ, the other end tapers gradually, attachment at or near the broad end (compare obovate, ovoid)
to trigonoustrigonous:
3D shape—having three faces that meet at distinct angles; triangular in outline
, roundround:
2D shape—orbiculate; circular
in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
, sometimes with persistent stylar remnantstylar remnant:
remnant of a style
, one to many seeded, often 2 or 3 per fruit. Pericarppericarp:
fruit wall or fruit coat
yellow, indurateindurate:
texture—hardened or stony; yielding under strong pressure; not deformable without internal structural disruption
, membranousmembranous:
texture—extremely thin, pliable, and fairly tough
, smooth.

Seed globoseglobose:
3D shape—more or less spherical
to prismaticprismatic:
like a prism; with sharp, definite angles and flat sides
, tereteterete:
approximately circular in cross section; width and thickness approximately equal
or flattened in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
,1.2–3 mm long. Seed coat brown, black, or white, dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
, membranousmembranous:
texture—extremely thin, pliable, and fairly tough
, smooth or variously sculptured, with a flattened appendage (Maschalocephalus, Monotrema, Potarophytum, Windsorina,) or without, sometimes with a conspicuous rapheraphe:
a ridge or seam on the seed coat, formed by the portion of the funiculus united to the ovule wall in longitudinally curved ovules
. Seed coats encrusted with silica and with large hiliums in Cephalostemon, Rapatea, and Spathanthus. Seeds of Cephalostemon usually have a white, conicalconical:
3D shape—cone-shaped, with the point of attachment at the broad end
or cap-like, spongyspongy:
soft, light, discontinuous but cohesive, and somewhat resilient
carunclescaruncles:
a localized outgrowth of the seed coat near the hilum of the seed; it functions as an elaiosome
or elaiosomeselaiosomes:
a lipid and protein-rich fleshy structure attached to some seeds and fruits, it attracts ants which then disperse the disseminule (e.g., caruncle in the Euphorbiaceae, the aril (outgrowth of the funiculus) in the Fabaceae)
.

Embryo rudimentaryrudimentary:
(of embryo) embryo is small and fills less than a quarter of the seed and can be variable in shapes, such as linear, spatulate, or oval
, lenticularlenticular:
3D shape—lens-shaped; biconvex
, straight, at micropylar end with flat side appressedappressed:
pressed close to or lying flat against something, as in hairs on grass bract
to endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
, 0.1 times the length of the endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
. Endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
copious, fleshyfleshy:
texture—fairly firm and dense, juicy or at least moist, and easily cut
or mealymealy:
loose, dry, and disintegrating in finely granular pieces like meal or flour
.

Identification features

Fruit
Type	capsulecapsule: a dry, dehiscent fruit formed by two or more carpels
Size range	3–10 mm long
Shape(s)	ovoid, oblongoblong: 2D shape—much longer than broad with nearly parallel sides, corners are rounded , globoseglobose: 3D shape—more or less spherical , ellipsoidellipsoid: 3D shape—elliptic , trigonous
Texture	indurate, membranous
Surface relief	smooth
Color(s)	yellow
Seed
Size range	1.2–3 mm long
Shape(s)	oblong, globoseglobose: 3D shape—more or less spherical , ellipsoidellipsoid: 3D shape—elliptic , teardrop-shapedteardrop-shaped: 2D shape—widest point is toward one end of the fruit, the other end tapers sharply to a pointed end , fusiformfusiform: spindle-shaped; broadest at the middle and tapering at both ends , prismaticprismatic: like a prism; with sharp, definite angles and flat sides , C-shapedC-shaped: 2D-shape—semiannulate, curved into the shape of the letter 'C' , lens-shapedlens-shaped: 2D shape—round and flattened with two curved (convex) surfaces , ovoidovoid: 3D shape—ovate , reniform
Surface relief	reticulate, striatestriate: surface relief—having fine, parallel lines, grooves or ridges , alveolatealveolate: surface relief—reticulated, honeycombed; ridges that intersect to form polygonal cells with a regular size and shape similar to a honeycomb , punctatepunctate: surface relief—dotted with pits or with translucent, sunken glands or with colored dots, similar to pitted , glandularglandular: surface relief—covered with small, raised secretory glands, regular or irregularly shaped, translucent or opaque, and maybe distinctly colored , papillatepapillate: surface relief—bearing minute, distinct, broad-based projections, tapering to a rounded apex , wrinkledwrinkled: surface relief—shallow, irregular folds and furrows covering the surface; appearing overall though crumpled and then spread out , spiny
Color(s)	brown, black, white
Other
Embryo	rudimentary, lenticularlenticular: 3D shape—lens-shaped; biconvex , straight, at micropylar end with flat side appressedappressed: pressed close to or lying flat against something, as in hairs on grass bract to endospermendosperm: nutritive starch- and oil-containing tissue present in many seeds , 0.1 times the length of the endosperm
Nutritive tissuenutritive tissue: tissue within the seeds that nourishes the developing embryo; such as endosperm, perisperm, or chalazosperm in angiosperms; megagametophyte in gymnosperms	endosperm endosperm: nutritive starch- and oil-containing tissue present in many seeds copious, fleshyfleshy: texture—fairly firm and dense, juicy or at least moist, and easily cut or mealy

Distribution

Tropics, South America, West Africa.

Distribution map courtesy of Angiosperm Phylogeny Website.

References

Baskin and Baskin 2021Baskin and Baskin 2021:
Baskin C and Baskin J. 2021. Relationship of the lateral embryo (in grasses) to other monocot embryos: A status up-grade. Seed Science Research 31 (3): 199-210. doi:10.1017/S0960258521000209; Berryet al. 1995Berryet al. 1995:
Berry PE, Holst BK, and Yatskievych K. 1995. Flora of the Venezuelan Guayana. Missouri Botanical Garden, St. Louis MO. 6,543 pp. (all volumes); Dahlgren et al. 1985Dahlgren et al. 1985:
Dahlgren RMT, Clifford HT, and Yeo PF. 1985. The families of the monocotyledons: structure, evolution, and taxonomy. Springer-Verlag, Berlin. 520 pp.; de S. Praia et al. 2016de S. Praia et al. 2016:
de S. Praia T, dos S. Braganccedil;a Gil A, and Secco Ricardo de S. 2016. Rapateaceae in the state of Paraacute;, Brazil. Acta Botanica Brasilica 30 (4): 628ndash;643. https://doi.org/10.1590/0102-33062016abb0162; Kirkbride et al. 2006Kirkbride et al. 2006:
Kirkbride JH, Jr, Gunn CR, and Dallwitz MJ. 2006. Family guide for fruits and seeds, vers. 1.0. Accessed September 2020ndash;January 2022. URL: https://nt.ars-grin.gov/seedsfruits/keys/frsdfam/index.cfm .; Kubitzki et al. 1990+Kubitzki et al. 1990+:
Kubitzki K et al., eds. 1990+. The families and genera of vascular plants. 7+ vols. Berlin etc.; Stevenson and Loconte 1995Stevenson and Loconte 1995:
Stevenson DW and Loconte H. 1995. A cladistic analysis of monocot families. In: Rudall PJ, Cribb PJ, Cutler DF, and Humphries CJ, eds. Monocotyledons: Systematics and Evolution. Royal Botanic Gardens, Kew.

*The number of genera and species is based on Christenhusz and Byng 2016Christenhusz and Byng 2016:
Christenhusz MJM and Byng JW. 2016. The number of known plant species in the world and its annual increase. Phytotaxa 261 (3): 201ndash;217. https://doi.org/10.11646/phytotaxa.261.3.1, which may differ from the number of genera in GRIN-Global.