Hydnoraceae

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

Hydnoraceae C. Agardh

Common name: Hydnora Family.

Number of genera: 2 genera.

Number of species (Mabberley 1997): 17 species.

Disseminule

Fruit (dehisced), or fruit (intact or entire), or seed.

Description

Fruits: Pistil(s) compound; 1; 1-pistillate; with carpels united. Fruit pericarpium; simple; amphisarcum, or capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
(not Spjut); pyxidium capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
; capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
not inflated; capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
without operculumoperculum:
a dehiscent cap (or lid) of a seed or fruit that opens during germination or dehiscence
; without persistent central column; many-seeded; 1000-seeded (+); from 5.1–10 cm long, or more than 10 cm long; 10–15 cm long (width); with 3(–4)-carpellate; with carpels remaining united at maturity; without sterilesterile:
lacking male and/or female reproductive parts; also, not producing fruit or seed
carpels; not sulcatesulcate:
surface relief—having one or more elongate, relatively narrow and shallow depressions or grooves
; apexapex:
the point farthest from the point of attachment, or the "tip" of an organ
not beaked; indehiscentindehiscent:
not opening on its own, as in a fruit
, or dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
. Dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
unit seed(s). Dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
regularly, or irregularly; passively; and shedding seeds; without replumreplum:
the rim, formed by the persistent placentas, and connected by a false septum in Brassicaceae fruits. The fruit valves are attached to this rim and separate from it in dehiscent fruits.
. Epicarpepicarp:
outer layer of fruit wall or pericarp, if divided into layers; note here used synonymously with exocarp
dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
; durable; hard; glabrousglabrous:
without hairs
; without armature; not smooth; scalyscaly:
surface relief—covered with small, thin, fine scales or flakes that may be removable
; without wing(s); without apicalapical:
at or pertaining to the end of the seed or fruit distal from its point of attachment (i.e., base)
respiratory hole. Mesocarpmesocarp:
the middle layer of the pericarp, if divided into layers
present; fleshy; composed of 1 unified layer; without lactiform cavity system. Endocarpendocarp:
the inner layer of the pericarp, if divided into layers
present, or absent; not separating from exocarpexocarp:
outer layer of fruit wall or pericarp, if divided into layers; note here used synonymously with epicarp
; thin; not splitting into 1-seeded pyrenes; without operculumoperculum:
a dehiscent cap (or lid) of a seed or fruit that opens during germination or dehiscence
; without secretory cavities; without longitudinallongitudinal:
of or relating to length or the lengthwise dimension
ridges. Funiculusfuniculus:
(alt. funicle) stalk connecting the ovule (later seed) to the ovary (later fruit) placenta
short; short without seed bearing hookswith hooks:
bristles or spines with curved or backwards pointing tips, or with secondary bristles along their length
(retinacula); not persisting in fruit after seed shed.

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 minute; 1 to less than 5 mm long; 1–1.8 mm long; irregular, or 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
; 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 endosperm, or perispermperisperm:
seed nutritive tissue comparable to the endosperm, but derived from the nucellus (maternal tissue)
; without canavanine. Sarcotestasarcotesta:
pulpy or fleshy outer layer of the seed coat, simulates aril
absent. Testatesta:
seed coat
present; without markedly different marginalmarginal:
at, on, or close to the margin or border
tissue; without fleshy or leatheryleathery:
texture—moderately thick, tough, and very pliable
layer over hard layer; loose; surface smooth, or unsmooth; surface with depressed features; surface pittedpitted:
surface relief—surface with small depressions in which the areas between the hollows do not take on the appearance of a true reticular net
; 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); hard; not becoming mucilaginousmucilaginous:
resembling mucilage; moist and sticky
when wetted; surrounding food reserve. Hilumhilum:
on seeds, the scar indicating where the funiculus was attached; on grass caryopses, the scar visible on the outer fruit surface revealing where the seed is attached on the inner fruit wall surface; or in Asteraceae cypselae, the scar visible on the outer fruit wall revealing where the fruit was attached to the receptacle
punctate. Endosperm development cellular; moderate; cartilaginouscartilaginous:
texture—firm, dense, tough, somewhat pliable, and resilient, like cartilage
; without fatty acid containing cyclopropene; with polysaccharide (arabinous) & acetic acid; 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. Perispermperisperm:
seed nutritive tissue comparable to the endosperm, but derived from the nucellus (maternal tissue)
scanty; opaqueopaque:
not transmitting light
. Embryo differentiated from food reserve; well developed; 1 per seed; partially filling testatesta:
seed coat
(with food reserve); 0.3 times the length of food reserve; at one end of seed not extending into a depression or cup; miniature; micro; straight; parallel to seed length; embedded in endosperm; without coleorhiza; without simmondsin; without stomata; not green; acotyledonous.

Distribution

General distribution: Old World, New World.

Detailed distribution: Prosopanche: Paraguay to Patagonia and now Central America Middle America, South America, and Africa (Hydnora: Ethiopia to the Cape & Madagascar).

Notes

Seeds immersed in gelatinous pulp.

References

Literature specific to this family: Musselman, L.J. & J.H. Vissar. 1989. Taxonomy and natural history of Hydnora (Hydnoraceae). Aliso 12:317–326; Cocucci, A.E. 1976. Estudios en el género Prosopanche (Hydnoraceae). III. Embriologia. Kurtziana 9:19–39.

General references: Corner, E.J.H. 1976. The seeds of Dicots, esp. vol. 2. Cambridge University Press, New York, Cronquist, A. 1981. An integrated system of classification of flowering plants, 1,262 p. Columbia University Press, New York, Engler, A. & K. Prantl. 1924 and onward. Die Natürlichen Pflanzenfamilimien. W. Engelman, Leipzig, Gaertner, J. 1788–1805. De fructibus et seminibus plantarum. The Author, Stuttgart, Goldberg, A. 1986 (dicots) & 1989 (monocots). Classification, evolution, and phylogeny of the familes of Dicotyledons. Smithsonian Contr. Bot. 58 for dicots (314 pp.) & 71 for monocots (74 pp.). [Goldberg's illustrations are reproduced from older publications and these should be consulted], 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, LeMaout, E. & J. Decaisne. 1876. A general system of botany, 1,065 p. Longmans, Green, & Co., London, Mabberley, D.J. 1987. The plant-book, 706 p. Cambridge University Press, Cambridge, and Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.