Ceratophyllaceae

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

Ceratophyllaceae S.F. Gray

Common name: Hornwort Family.

Number of genera: 1 genus.

Number of species (Mabberley 1997): 2 species (Ceratophyllum demersum L., C. submersum L.).

Disseminule

Fruit (intact or entire).

Description

Fruits: Pistil(s) simple; 1; 1-pistillate. Fruit pericarpium; simple; acheneachene:
a dry, indehiscent, one-seeded fruit, with seed attached to pericarp at a single point, derived from a single, superior, simple or compound, one-loculed ovary
(Spjut Fig. 3D-E); without persistent central column; with styles(s) (often spinyspiny:
having slender, stiff, sharp projections oriented in the general plane of the structure
); at apexapex:
the point farthest from the point of attachment, or the "tip" of an organ
; not within accessory organ(s); 1-seeded; 1-seeded; with 1-carpellate; in transection tereteterete:
approximately circular in cross section; width and thickness approximately equal
(ovoidovoid:
3D shape—ovate
or ellipsoidellipsoid:
3D shape—elliptic
); apexapex:
the point farthest from the point of attachment, or the "tip" of an organ
not beaked; wall hard; indehiscentindehiscent:
not opening on its own, as in a fruit
. Epicarpepicarp:
outer layer of fruit wall or pericarp, if divided into layers; note here used synonymously with exocarp
durable; crustaceouscrustaceous:
texture—thin, dry, indurate, and brittle
, or leatheryleathery:
texture—moderately thick, tough, and very pliable
; glabrousglabrous:
without hairs
; with armature, or without armature; with spines; without armature glochidiate; smooth, or not smooth; warted; 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. Endocarpendocarp:
the inner layer of the pericarp, if divided into layers
present; 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; smooth; without wing; without operculumoperculum:
a dehiscent cap (or lid) of a seed or fruit that opens during germination or dehiscence
; without secretory cavities; without mechanism for seedling escape; without grooves; 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; in transection sub 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 without food reserves, or with food reserves; with endosperm; without canavanine. Sarcotestasarcotesta:
pulpy or fleshy outer layer of the seed coat, simulates aril
absent. Testatesta:
seed coat
present; without fleshy or leatheryleathery:
texture—moderately thick, tough, and very pliable
layer over hard layer; surface smooth, or unsmooth; surface with depressed features; surface groovedgrooved:
surface relief—linear depressions that may be single or form a series of grooves over the surface
(caused by embryo); 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; thin, or membranousmembranous:
texture—extremely thin, pliable, and fairly tough
; not becoming mucilaginousmucilaginous:
resembling mucilage; moist and sticky
when wetted. 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. Embryo differentiated from food reserve; well developed; 1 per seed; completely filling testatesta:
seed coat
(no food reserve); at one end of seed not extending into a depression or cup; straight; parallel to seed length; without coleorhiza; without simmondsin; without stomata; green; with 2 or more cotyledons. Cotyledons 2; 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 vestigial; not thickened. Plumule well developed; composed of several seed-leaves; straight; terminal between 2 cotyledons.

Habitat and crop association

Noxious weeds: 1 or more USA state noxious weeds in this family.

USA states and territories with listed noxious weeds: Puerto Rico (PR).

USA state and territory noxious weeds:

Ceratophyllum demersum L.: USA state noxious weed: PRª.

Ceratophyllum spp.: USA state noxious weed: PRª.

Symbols: ªaquatic weed; ●terrestrial weed; °weed in seed.

Last updated February 2006.

Distribution

General distribution: Cosmopolitan (except for colder parts of Northern Hemisphere). New World and Old World.

Detailed distribution: North America to Oceania.

References

Literature specific to this family: Wilmot-Dear, M. 1985. Ceratophyllum revised: A study in fruit and leaf variation. Kew Bull. 40:243–271; Muenscher, W.C. 1940. Fruits and seedlings of Ceratophyllum. Amer. J. Bot. 27:231–233.

General references: Baillon, H.E. 1866–95. Histoire des plantes, 13 vols. Hachette & Co., Paris, 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, 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.