Podostemaceae

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

Podostemaceae L. Richard ex C. Agardh

Common name: Riverweed Family.

Number of genera: 48 genera.

Number of species (Mabberley 1997): 275 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, or schizocarpschizocarp:
usually dry fruit splitting between two or more locules to form distinct, indehiscent, usually one seeded segments; fruit derived from a single, superior or inferior, compound ovary; compare to mericarp
; capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
; coccarium; septicidalsepticidal:
type of capsular dehiscence, opening longitudinally by separating between the septa of adjacent carpels
capsulecapsule:
a dry, dehiscent fruit derived from a compound ovary
, or 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
(of authors, but 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
; without persistent central column; not within accessory organ(s); more than 1 but less than 10-seeded to many-seeded; 2-seeded (to many); less than 1 cm long; (02.8-)03.5–0.42; with (1–)2(–3)-carpellate; with carpels united; 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
; 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; indehiscentindehiscent:
not opening on its own, as in a fruit
, or dehiscentdehiscent:
(v. dehisce) splitting open at maturity to release contents (of a fruit)
(Farmeria). 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)
at apexapex:
the point farthest from the point of attachment, or the "tip" of an organ
; 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; glabrousglabrous:
without hairs
; without armature; not smooth; ribbedribbed:
surface relief—wide, prominent, linear ridges that are generally rounded and longitudinally situated on the surface
(6–14 longitudinally); 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 larger than minute; less than 1 mm long; 0.25–0.27 mm long; ellipsoidellipsoid:
3D shape—elliptic
, or obovoidobovoid:
3D shape—obovate
, or circularcircular:
(of embryo) linear embryo is curved into an "O" shape
(sub); in transection compressedcompressed:
flattened; in grasses, used to denote compression (not necessarily flattened) either laterally or dorsiventrally
; 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; 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; 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; 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; "dark"; membranousmembranous:
texture—extremely thin, pliable, and fairly tough
; becoming mucilaginousmucilaginous:
resembling mucilage; moist and sticky
when wetted; surrounding embryo. 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. Embryo differentiated from food reserve; well developed; 1 per seed; completely filling testatesta:
seed coat
(no food reserve); 1 times the length of food reserve; at one end of seed not extending into a depression or cup; straight; without coleorhiza; without simmondsin; with cotyledons containing oils; without stomata; not green; with 2 or more cotyledons. Cotyledons 2; moderately thick; equal in size, or unequal in size; more or less unequal; not punctatepunctate:
surface relief—dotted with pits or with translucent, sunken glands or with colored dots, similar to pitted
dotted. Hypocotyl-radicle small; not thickened.

Distribution

General distribution: Cosmopolitan. New World and Old World.

Detailed distribution: North America to Oceania.

Notes

Classify, according to Spjut, the indehiscentindehiscent:
not opening on its own, as in a fruit
fruit of Farmeria with 2 equal valves (caducous and deciduousdeciduous:
falling off; not persistent
) each with 3 or 5 ribs or 6–14 ribs. Fruit slightly protruding beyond spathilla.

References

Literature specific to this family: Royen, P. van. 1951. The Podostemaceae of the New World. Part I. Meded. Bot. Mus. Herb. Rijks. Univ. Utrecht 107:1–151, pls. 1–16; Royen, P. van. 1953. The Podostemonaceae of the New World. II. Acta Bot. Neerl. 2:1–21; Royen, P. van. 1954. The Podostemonaceae of the New World. III. Acta Bot. Neerl. 3:215–263; Novelo R., A. & C.T. Philbrick. 1993. Vanroyenella: A new genus of Podostemaceae from Jalisco, Mexico. Syst. Bot. 18:64–67.

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, 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, Hooker, J.D. 1873 and forward. Icones Plantarum. William & Norgate, London. (plate number cited in text within [ ]), and Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.