Viscaceae

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

Viscaceae Batsch

Common name: Christmas-mistletoe Family.

Number of genera: 7 genera.

Number of species (Mabberley 1997): 450 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; berryberry:
an indehiscent, fleshy fruit with one or a few to many seeds. The flesh may be homogenous throughout. Or, if the outer part is hard, firm, or leathery, referred to as an hesperidium. Septa are present in some, and the seeds may be arillate or with a fleshy testa.
; berryberry:
an indehiscent, fleshy fruit with one or a few to many seeds. The flesh may be homogenous throughout. Or, if the outer part is hard, firm, or leathery, referred to as an hesperidium. Septa are present in some, and the seeds may be arillate or with a fleshy testa.
dehiscent (at least epicarpepicarp:
outer layer of fruit wall or pericarp, if divided into layers; note here used synonymously with exocarp
separates or may explode); berryberry:
an indehiscent, fleshy fruit with one or a few to many seeds. The flesh may be homogenous throughout. Or, if the outer part is hard, firm, or leathery, referred to as an hesperidium. Septa are present in some, and the seeds may be arillate or with a fleshy testa.
without central placental mass; without persistent central column; not within accessory organ(s); 1-seeded to more than 1 but less than 10-seeded; 1(–2)-seeded; less than 1 cm long, or from 1–5 cm long; 0.6–2.3 cm long; with 3–4-carpellate; with carpels united; with carpels remaining united at maturity; with carpels not radiating at maturity; with carpels remaining connected at stylestyle:
in a flower, the narrow and elongated part of the pistil between the stigma and the ovary; sometimes persisting in fruit
; 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
; in transection tereteterete:
approximately circular in cross section; width and thickness approximately equal
; apexapex:
the point farthest from the point of attachment, or the "tip" of an organ
not beaked; wall fleshy; dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
, or indehiscentindehiscent:
not opening on its own, as in a fruit
. Dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
unit mesocarp(s). Dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
irregularly; actively, or passively; explosively; but retaining seed(s); 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
shiny; durable; glabrousglabrous:
without hairs
; without armature; smooth; 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; viscous, or watery (Barlow (1964) noted viscous layer inside the vascular bundles. Contrast with Loranthaceae. Viscum capense L. f. is watery, not viscid.); 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; 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 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 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; without canavanine. Sarcotestasarcotesta:
pulpy or fleshy outer layer of the seed coat, simulates aril
absent. Testatesta:
seed coat
absent; with embryo surrounded and capped at one end with viscid tissue. Endosperm smooth; with starch; 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; with chlorophyll and green; without isodiametric faceted surface; without odor. Embryo differentiated from food reserve; well developed; 1 per seed; nearly filling testatesta:
seed coat
(trace or scanty food reserve), or partially filling testatesta:
seed coat
(with food reserve); 0.4–0.8 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; foliatefoliate:
appearing leaf-like
, or linearlinear:
(shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide
; with spatulatespatulate:
2D shape—like a spatula; rounded at the apex, with base long and tapered; (of embryo) embryo is straight and axile and centric with the cotyledons expanded to form the shape of a spatula or spoon; (of cotyledons) cotyledons expanded and wider than the stalk but not invested into the stalk
cotyledons; straight; parallel to seed length; embedded in endosperm; with cotyledons abruptly connected to hypocotyl-radicle, or gradually connected to hypocotyl-radicle; without coleorhiza; without simmondsin; without stomata; not green; with 2 or more cotyledons. Cotyledons 2; well developed; 0.3–0.7 times length of embryo; as wide as hypocotyl-radicle, or somewhat to significantly wider than hypocotyl-radicle; 1–3 times wider than hypocotyl-radicle (estimated); not concealing hypocotyl-radicle; foliaceous, or not foliaceous; thin; 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 well developed, or moderately developed; straight; not thickened.

Habitat and crop association

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

USA states and territories with listed noxious weeds: California (CA).

USA state and territory noxious weeds: 

Viscum album L.: USA state noxious weed: CA●. 

Symbols: ªaquatic weed; ●terrestrial weed; °weed in seed. 
Last updated February 2006.

Distribution

General distribution: Cosmopolitan. New World and Old World.

Detailed distribution: North America to Oceania.

Notes

Goldberg did not cover this family.

References

Literature specific to this family: Edouard, J.-A. & A. Raynal-Roques. 1989. Le fruit des guis (Loranthaceae et Viscaceae): utilité pour la taxonomie et mode des dissémination par les oiseaux. Bull. Mus. Natl. Hist. Nat., B, Adansonia 3:307–314; Barlow, B.A. 1964. Classification of the Loranthaceae and Viscaceae. Proc. Linn. Soc. New South Wales 89:268–272.

General references: 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, 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, 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.