Garden Asparagus

Eaten as a vegetable, Asparagus officinalis has been widely cultivated for its young shoots since ancient Greek times. The species is naturalized in many temperate climates. Mature asparagus has caused poisoning in cattle (J. M. Kingsbury 1964). Young plants can cause dermatitis, and the red berries are suspected of poisoning humans (E. M. Schmutz and L. B. Hamilton 1979). The species is dioecious (J. E. Lazarte and B. F. Palser 1979), and homomorphic sex chromosomes have been identified (H. Loptien 1979).

A very variable species; some cultivars are grown as a vegetable in China.

Herbs, erect, 1–2.5 m; rhizomes fibrous. Stems annual, densely branched distally; branches finely dissected, ascending to perpendicular, unarmed; cladophylls in clusters of (2–)4–15(–25) per node, filiform, straight or curved, 1–3 cm. Leaves scalelike, 3–4 mm; blade lanceolate, base hardened. Inflorescences in axillary racemes, 1–3-flowered. Flowers some unisexual; perianth campanulate, yellow or yellowish green; tepals connate 1–2 mm, greenish white, 3–8 × 1–2 mm; pedicel 8–12 mm, jointed at or above middle. Berries red, 6–10 mm. Seeds 2–4. 2n = 20, 40.

Herbs dioecious. Roots 2--3 mm thick, rather slender. Stems suberect, to 1 m, usually slightly pendent apically; branches soft. Cladodes in fascicles of 3--6, 0.5--3 cm × ca. 0.4 mm, subterete, slightly flattened, irregularly grooved. Leaf spur slightly spinescent or indistinct. Inflorescences developing after cladodes. Flowers of both sexes solitary of in clusters of 2--4; pedicel 0.8--1.2(--1.4) cm. Male flowers: perianth yellowish green, campanulate, 5--6 mm; filaments adnate to perianth segments for ca. 1/2 their length; anthers 1--1.5 mm. Female flowers: perianth ca. 3 mm. Berry red, 7--8 mm in diam., 2- or 3-seeded. Fl. May--Jun, fr. Aug. 2 n = 20*, 40.

introduced; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Sask.; Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; Asia; n Africa; naturalized in temperate regions worldwide.

Flowering summer.

Fields, fencerows, roadsides, disturbed areas; 0--2500m.

Steppes. NW Xinjiang [Kazakhstan, Mongolia, Russia; NW Africa, C and SW Asia, Europe, widely cultivated elsewhere].

Asparagus officinalis var. altilis Linnaeus; A. polyphyllus Steven.