Clethraceae

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

Clethraceae J. Klotzsch

Common name: Clethra Family.

Number of genera: 1 genus.

Number of species (Mabberley 1997): 64 species.

Disseminule

Fruit (dehisced), or seed.

Description

Fruits: Pistil(s) compound; 1; 1-pistillate; with carpels united. Fruit pericarpium; simple; capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
; septifragalseptifragal:
type of capsular dehiscence, splitting through the exterior wall suture(s) but not the septum(-a), the valves of the wall then separating from the septum(-a) and the locules thus opened directly to the outside
capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
(Spjut), or loculicidalloculicidal:
type of capsular dehiscence, opening longitudinally through the locules (compare septicidal)
capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
(of authors, not Spjut); 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
; with persistent central column; valves not diverging at top of central column; not within accessory organ(s); 10 to less than 25-seeded; many; with 3-carpellate; with carpels united; 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; 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; 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
durable; without armature; not smooth; tuberculatetuberculate:
surface relief—bearing small, warty, swelling, rounded, or variously shaped projections
, or verrucoseverrucose:
surface relief—warty, covered with wart-like projections
; 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 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; 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
present; without fleshy or leatheryleathery:
texture—moderately thick, tough, and very pliable
layer over hard layer; surface unsmooth; surface with merged raised features; surface reticulatereticulate:
surface relief—netted, raised walls or concave grooves forming a net-like surface pattern with flat, concave, or convex interspaces
; 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; with wing(s), or without wings (seldom); 2-winged; with wings on both sides; without collar; without operculumoperculum:
a dehiscent cap (or lid) of a seed or fruit that opens during germination or dehiscence
; colored; monochrome; thin (single cell layer); not becoming mucilaginousmucilaginous:
resembling mucilage; moist and sticky
when wetted; surrounding food reserve. Endosperm development cellular; moderate (copious according to Mabberley); fleshy; smooth; with oils; 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; partially filling testatesta:
seed coat
(with food reserve); 0.9 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
; straight; parallel to seed length; with cotyledons abruptly connected to hypocotyl-radicle; without coleorhiza; without simmondsin; without stomata; not green; with 2 or more cotyledons. Cotyledons 2; well developed; 0.25 times length of embryo; somewhat to significantly wider than hypocotyl-radicle; smooth; with apicesapex:
the point farthest from the point of attachment, or the "tip" of an organ
entire; with margins separate; basally cordatecordate:
2D shape—heart-shaped, with attachment at or near the broad end (compare obcordate)
(more or less); 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; coiledcoiled:
(of embryo) linear embryo is very long and bent to form a coil whereby one end of the embryo is on the outside and the other end near the middle of the seed
; not thickened.

Distribution

General distribution: Cosmopolitan. New World and Old World.

Detailed distribution: North America, Middle America, South America, Asia Major, and Asia Southeastern (to Japan & China).

Notes

Spjut recorded septigragal capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
because of "incompletely opening along the dorsaldorsal:
abaxial; the back of an organ; the side away from the axis (compare ventral)
or ventralventral:
adaxial; of the side of an organ facing the axis (compare dorsal)
sutures by break in partitions near central axisaxis:
a straight line through the center of a structure around which the parts are usually symmetrically arranged, as in the stem or rachis of an inflorescence
, leaving a persistent columellacolumella:
any pedestal-like prolongation of a floral receptacle extending beyond the distalmost level of perianth insertion and bearing the gynoecium; the stalk supporting a mericarp after dehiscence of a schizocarpic fruit, the central axis of the fruit having split longitudinally to yield two or four such stalks; composed of receptacular and (primarily) gynoecial tissues, especially in Apiaceae. See carpophore.
. often valves have separated". Fernald (1950) "placentaplacenta:
surface of the ovary that bears ovules
e remaining attached to the columellacolumella:
any pedestal-like prolongation of a floral receptacle extending beyond the distalmost level of perianth insertion and bearing the gynoecium; the stalk supporting a mericarp after dehiscence of a schizocarpic fruit, the central axis of the fruit having split longitudinally to yield two or four such stalks; composed of receptacular and (primarily) gynoecial tissues, especially in Apiaceae. See carpophore.
".

References

Literature specific to this family: Fernald, M.L. 1950. Gray's Manual of Botany, 8th Ed., 1,632 p. American Book Co., New York.

General references: 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, and Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.

 Fruit:  Clethra arborea ; Photo by R. Gibbons, USDA APHIS PPQ, Kirkbride et al. (2006)
Fruit: Clethra arborea; Photo by R. Gibbons, USDA APHIS PPQ, Kirkbride et al. (2006)
 Fruit:  Clethra arborea ; Photo by R. Gibbons, USDA APHIS PPQ, Kirkbride et al. (2006)
Fruit: Clethra arborea; Photo by R. Gibbons, USDA APHIS PPQ, Kirkbride et al. (2006)
 Seed:  Clethra arborea ; Photo by R. Gibbons, USDA APHIS PPQ, Kirkbride et al. (2006)
Seed: Clethra arborea; Photo by R. Gibbons, USDA APHIS PPQ, Kirkbride et al. (2006)
 Embryo:  Clethra arborea ; Illustration by K. Parker, Kirkbride et al. (2006)
Embryo: Clethra arborea; Illustration by K. Parker, Kirkbride et al. (2006)
 Embryo:  Purdiaea cubensis ; Illustration by K. Parker, Kirkbride et al. (2006)
Embryo: Purdiaea cubensis; Illustration by K. Parker, Kirkbride et al. (2006)