Alhagi

Taxonomy

Alhagi F. Gagnepain Acta Helv. Phys.-Math. 2: 59. Feb 1755.

Subfamily: Faboideae.
Phylogenetic Number: 3.16.21.
Tribe: Galegeae.
Subtribe: Alhagiinae.
Species Studied - Species in Genus: 3 studied; 3 in genus.

Description

Fruit: A legume, or a loment (or a loment segment) (only tardily separating: see Notes); unilocular; 0.8–2 cm long; 0.2–0.4 cm wide; 0.2–0.4 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight, or curved (or slightly curved); not plicate; not twisted; asymmetrical; linear, or moniliform; with both sutures unequally curved, or 1 straight and 1 curved suture, or both sutures nearly straight; narrowing in several places, resembling Desmodium (3.11.09) fruit; not inflated; terete; with beak; straight, or declined; with solid beak the same color and texture as fruit; rounded at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous, or coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin constricted (some constrictions may be well developed), or not constricted; margin constricted along both margins, or constricted only on 1 margin; margin without sulcus; margin plain; wing(s) absent; substipitate, or stipitate (because of aborting of lowest seed chamber); with the stipe 0.1–5 mm long; indehiscent. Replum invisible. Loment indehiscent; segments (articles) widest across seed area; segments (articles) oblong. Epicarp dull; monochrome; reddish to blackish brown, or tan; with surface texture uniform; glabrous, or pubescent and indurate (especially between seed chamber), or pubescent but soon deciduous; with hairs appressed, or erect; with 1 type of pubescence; sericeous (to sparingly); with pubescence gray; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; glandular, or eglandular; with glandular dots (reddish-brown); without spines; smooth, or not smooth; with elevated features; not veined; not tuberculate; warty, or wrinkled; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 2-layered; without balsamic vesicles; without fibers; without reniform canals; with solid layer over vitriol layer; coriaceous. Endocarp present; visible; dull; opaque; monochrome, or mottled; white; with mottling more or less uniform (dark); with brown overlay (reddish-brown (vitriol layer of mesocarp)); smooth; without adhering pieces of testa; septate; with septa thicker than paper, firm; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–9; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; thick; straight. Aril present; dry; when dry rim-aril; entire; blackish brown, or black.

Seed: 2–3 mm long; 0.8–2.3 mm wide; 1.3 mm thick; overgrown, 1 seed filling entire fruit cavity; angular; asymmetrical; reniform, or quadrangular; compressed; with surface smooth; with visible radicle and cotyledon lobes; with external groove between radicle and cotyledon lobes, or without external groove between radicle and cotyledon lobes; with external groove between radicle and cotyledon lobes same color as testa; without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; monochrome, or mottled; with frequent mottles; brown to blackish brown, or tan, or yellow, or green, or black; with black overlay (to purplish black); glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; punctiform; between cotyledon and radicle lobe; recessed; not within corona, halo, or rim. Lens discernible; 0.5 mm long; with margins straight; diamond-shaped, or irregular; not in groove of raphe; confluent with hilum, or adjacent to hilum; 0.1 mm from hilum; mounded; dissimilar color from testa; darker than testa; blackish brown, or black; not within corona, halo, or rim. Endosperm present; thick; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to embryo. Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; not concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; white; inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; deflexed and parallel to cotyledon length; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Mediterranean region to Nepal.

Old World; southern Europe to Mediterranean to Russia to Africa to Southwest Asia to China to Mongolia to India (to Nepal, North Africa).

Generic Notes

Polhill (1981h) noted that Alhagi is usually placed in the Hedysareae, "but as discovered there the flowers and fruits do not agree well with the current narrow circumscription of that tribe." Yakovlev (1979) discussed the species, A. maurorum, in the former U.S.S.R. Hutchinson (1964) reported "embryo covered by a fleshy membrane," which is the endosperm adnate to the embryo. The fruit of Alhagi is technically and functionally an indehiscent legume and not a loment, notwithstanding the fact that the fruits may tardily and irregularly fracture at the isthmuses which occur between seed chambers. The fruit has been described accurately as lomentoid or lomentaceous, and recognizing this situation we have scored it both ways. Pandey and Jha (1988) described the testa of A. maurorum using the SEM.

Tribal Notes

Tribe Galegeae

Traditionally this tribe has been called Galegeae. Reveal (1997) reported that the name Astragaleae was published before the name Galegeae. Following the International Code of Botanical Nomenclature (Greuter et al., 1994), the oldest name for a taxon must be used, so Reveal suggested that this tribe should be called Astragaleae. In 1999 Reveal (1999) reversed himself, so that this tribe remains the Galegeae. Welsh (1960) reported on the Galegeae of north-central United States. Sanderson and Liston (1995) carried out cladistic analyses of Galegeae genera using molecular data. They concluded that Galegeae is paraphyletic having given rise to tribes Cicereae (20), Hedysareae (18), Trifolieae (21), and Fabeae (19), and therefore requiring a re-evaluation of the circumscription of Galegeae. Heenan (1995, 1998c), utilizing unpublished nuclear ribosomal DNA ITS data, concluded that "Carmichaelia (17.05) is nested within (the) 'Astragalean clade' of Galegeae" and is the sister group of Clianthus. He therefore supported the proposal of Sanderson and Wojciehowski (1996) that Carmichaelieae should not be recognized at tribal level, but rather included in Galegeae.