Gnetaceae

Disclaimer

Content is from 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 2020-January 2022. URL:  https://nt.ars-grin.gov/seedsfruits/keys/frsdfam/index.cfm ., without modification. 
Updates are forthcoming.

Taxonomy

Gnetaceae Blume

Common name: Gnetum Family.

Number of genera: 1 genus.

Number of species (Mabberley 1997): 28 species.

Disseminule

Cone, or seed.

Description

Cones: Fleshyfleshy:
texture—fairly firm and dense, juicy or at least moist, and easily cut
; arcesthida when fleshyfleshy:
texture—fairly firm and dense, juicy or at least moist, and easily cut
(mimics a drupedrupe:
(indehiscent drupe) a fleshy, indehiscent fruit with one more hard pits enclosing seeds, derived from single, superior, simple or compound ovary; (dehiscent drupe) a fruit with a dry or fibrous to fleshy or leathery outer husk that early to tardily breaks apart (or opens), exposing one or more nutlike pits enclosing the seeds
with pink fleshyfleshy:
texture—fairly firm and dense, juicy or at least moist, and easily cut
or corkycorky:
firm, relatively light, discontinuous but strongly cohesive, and resilient
outer layer (from perianthperianth:
collective term for calyx and corolla of a flower
) & seed with bonybony:
very hard and rather brittle, like bone
testa. Spjut families: Gnetaceae & Cupressaceae (Juniperus).).

Seeds: Arilaril:
(broad sense) appendicular structure that wholly or partly envelops a seed and is produced from or a modification of the funicle, raphe, or outer integument; usually fleshy or pulpy, sometimes spongy or tufted-capillate, often brightly colored
absent. Seed larger than minute; oblongoblong:
2D shape—much longer than broad with nearly parallel sides, corners are rounded
, or circularcircular:
(of embryo) linear embryo is curved into an "O" shape
; in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
tereteterete:
approximately circular in cross section; width and thickness approximately equal
; not bowl shaped; not nutlike; without winglike beakbeak:
a usually firm, terminal appendage, sometimes tapered
; without caudatecaudate:
tapering to a long, tail-like appendage
appendage(s); at maturity with food reserves; with endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
; without canavanine. Sarcotestasarcotesta:
pulpy or fleshy outer layer of the seed coat, simulates aril
absent. Testatesta:
seed coat
present; with fleshyfleshy:
texture—fairly firm and dense, juicy or at least moist, and easily cut
or leatheryleathery:
texture—moderately thick, tough, and very pliable
layer over hard layer (with thinthin:
having or being of relatively little depth
layer below); tight; shinyshiny:
uniformly reflecting a high proportion of incident light at all angles
; surface unsmooth; surface with merged raised features; surface longitudinally striatestriate:
surface relief—having fine, parallel lines, grooves or ridges
; without crease or line separating cotyledons from hypocotyl-radicle; without notch along margin where cotyledons from hypocotyl-radicle tip approach each other; without glands; without bristles; glabrousglabrous:
without hairs
; without wings; without collar; without operculumoperculum:
a dehiscent cap (or lid) of a seed or fruit that opens during germination or dehiscence
; colored; monochrome; brown (all shades) (assumed); bonybony:
very hard and rather brittle, like bone
(best?); not becoming mucilaginousmucilaginous:
resembling mucilage; moist and sticky
when wetted; surrounding food reserve. Endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
copious; without fatty acid containing cyclopropene; without apicalapical:
at or pertaining to the end of the seed or fruit distal from its point of attachment (i.e., base)
lobes; without chlorophyll; without isodiametric faceted surface; without odor. Embryo differentiated from food reserve; well developed; 1 per seed (only matures, but several when immature); partially filling testatesta:
seed coat
(with food reserve); 1 times the length of food reserve; at one end of seed not extending into a depression or cup; axileaxile:
on or of the axis
and centric; linearlinear:
(shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide
(nearly); straight; parallel to seed length; with cotyledons gradually connected to hypocotyl-radicle; without coleorhiza; without simmondsin; without stomata; not green; with 2 or more cotyledons. Cotyledons 2; well developed; 0.75 times length of embryo; somewhat to significantly wider than hypocotyl-radicle; 1.2 times wider than hypocotyl-radicle; not concealing hypocotyl-radicle; not foliaceous; thinthin:
having or being of relatively little depth
; flat; smooth; with apicesapex:
the point farthest from the point of attachment, or the "tip" of an organ
entire; with margins separate; basally entire; equal in size; not punctatepunctate:
surface relief—dotted with pits or with translucent, sunken glands or with colored dots, similar to pitted
dotted. Hypocotyl-radicle moderately developed; straight; not thickened.

Distribution

General distribution: Pantropical. New World and Old World.

Detailed distribution: South America, Africa, Asia Minor, Asia Southeastern, and Australia.

References

General references: Gunn, C.R., J.H. Wiersema, C.A. Ritchie, & J.H. Kirkbride, Jr. 1992 & amendments. Families and genera of Spermatophytes recognized by the Agricultural Research Service. Techn. Bull. U.S.D.A. 1796:1–500, Kubitzki, K. 1990. Gnetatae with the single living order Gnetales. In: Kubitzki, K., ed., The families and genera of vascular plants, vol. 1, pp. 378–391. Springer-Verlag, Berlin, Mabberley, D.J. 1987. The plant-book, 706 p. Cambridge University Press, Cambridge, Martin, A.C. 1946. The comparative internal morphology of seeds. Amer. Midl. Naturalist 36:513–660, and Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.