Cannabis sativa subsp. indica var. afghanica (Vavilov) McPartl. & E.Small, 2020

McPartland, John M. & Small, Ernest, 2020, A classification of endangered high-THC cannabis (Cannabis sativa subsp. indica) domesticates and their wild relatives, PhytoKeys 144, pp. 81-112 : 81

Cannabis sativa subsp. indica var. afghanica (Vavilov) McPartl. & E.Small stat. nov. Figure 5

Cannabis sativa f. afghanica Vavilov, Trudy po Prikladnoi Botanike, Genetike i Selektsii 16(2): 227, 1926 (Basionym).

≡ C. indica var. afghanica Vavilov in Vavilov & Bukinich, Trudy Po Prikladnoi Botanike, Genetike i Selektsii 33 (Suppl.): 380, 1929, orthographic variant.

≡ C. indica var. kafiristanica f. afghanica Vavilov in Vavilov & Bukinich, Trudy Po Prikladnoi Botanike, Genetike i Selektsii 33: 381, 1929.

= C. sativa subsp. culta prol. asiatica var. narcotica Serebriakova in Serebriakova & Sizov, Kul’turnaya Flora SSSR 5: 36, 1940 (no Latin diagnosis and not typified).

= C. afghanica var. turkistanica Clarke, Cannabis Evolution p. 225, 1987, nomen invalidum.

= C. sativa var. afghanica McPartland, Hemp Diseases & Pests p. 4, 2000, nomen nudum.

= C. sativa var. afghan , Sands, U.S. patent 6,403,530, 2002, nomen nudum.

Neotype.

Designated herein: Afghanistan: Ghazni Province (formerly Kandahar Province), Gui-Akhen ( Гуй-Ахен) village near Qala-i Murvardar ( Кала-и Мурвардар), on the Ghazni-Kandahar road, Vavilov, 1924, from seed sown by Serebriakova in 1926 at North Caucasus Experiment Station, Maikop, Krasnodar Krai (labeled Cannabis sativa , WIR 609, 3945). Fig. 5a . No specimen labeled afghanica exists at WIR (McPartl., pers. observation, WIR 2010). The achene illustration in Vavilov and Bukinich (1929) cannot serve as lectotype because it is not part of the protologue, which appears in Vavilov (1926).

Epitype.

Designated herein, explicitly supporting the neotype: Afghanistan: Kandahar Province, near Kandahar, Schultes, XII.13-20.1971 (ECON 26505). Fig. 5b . The ICN defines an epitype as a specimen selected as an interpretive type when the holo-/lecto-/neotype is suboptimal for critical identification ( Turland 2018). ECON 26505 serves as an epitype because its morphology unambiguously agrees with the widespread concept of “Indica”. ECON 26505 also serves as a typotype - a photograph of the specimen, when alive and in the ground, which appears in Schultes et al. (1974), and is reproduced in Suppl. material 1: SF.8.

Diagnosis.

Plants with THC% ≥0.3% in inflorescence and a THC/CBD ratio <7 (almost always>1); central leaflet length:width ratio <6 in fan leaves near the base of inflorescences; mature achenes usually ≥ 3.6 mm long, the perianth mostly sloughed off, lacking a prominent protuberant base, and lacking a well-developed abscission zone that allows easy disarticulation.

Morphology.

Plants usually <2 m tall, often <1 m. Central stem (stalk) internodes short (often 5-11 cm), mostly solid, central hollow usually less than 20% of stalk diameter. Branches in well-developed plants begin close to ground level, at an angle sometimes nearly 90° from the stalk axis, producing a menorah-shaped habitus. Leaf palmately compound, largest leaves typically with 7-11 leaflets, leaflet edges often overlapping, color dark green ("black hemp" Vavilov 1992). Central leaflet long and broad, often oblanceolate in shape; margins with coarse serrations, secondary serrations rarely seen. Female inflorescence (and infructescence) compact, often agglutinated with trichome exudate, with prominent sugar leaves (a low perigonal bract-to-leaf index); short internode length causes axillary racemes become confluent and coalesce into collective congested colas. Sugar leaves with dense CSGTs on the proximal half, often present beyond the midpoint of the leaflet. Perigonal bract densely covered with CSGTs. Perianth membranous, usually sloughed off, with a fringe of striped or irregularly mottled pigmentation near the base of the fruit. Achene usually ≥ 3.6 mm long, exocarp green to gray; base blunt and lacking well-developed abscission zone.

Phytochemistry.

Dried female inflorescences: THC ≥0.3, in late 20th century accessions nearly always>1.0%; literature weighted x¯ = 5.69%, up to 14.5%. This variety expresses the highest total THC%+CBD% (a measure of relative resin content of the plants, since these two cannabinoids usually dominate the resin) of all varieties, which correlates with its dense covering of glandular trichomes. Its THCV%+CBDV% content is lower than South Asian populations; Hillig and Mahlberg (2004) report a mean of 0.14%. Terpenoid profile imparts an acrid or “skunky” aroma, and uniquely expresses sesquiterpene alcohols, such as guaiol, γ -eudesmol, β -eudesmol, and the monoterpene alcohol nerolidol, as well as hydroxylated terpenoids, such as γ -elemene, a -terpineol, and β -fenchol.

Genetics.

Allozyme and DNA studies that segregated Central Asian and South Asian domesticates are detailed in the genetics section of Variety 1. Onofri et al. (2015) identified a SNP in the gene that encodes THCA synthase that was unique in two Afghani accessions and a Moroccan " hashīsh landrace" (their SNP accession code no. 1179, A→T transversion). It was not present in 16 other accessions of fiber- and drug-type plants.

Other characters.

Generally early maturing, with greater late-season frost tolerance than South Asian domesticates. Late-season cold triggers anthocyanin production in leaves and inflorescences - the sought-after "purple weed." Achenes are mostly retained on plants, trapped by surrounding parts of the dense infructescence. Plants are more susceptible to gray mold ( Botrytis cinerea ) and powdery mildew ( Golovinomyces cichoracearum ) than South Asian domesticates.

Provenance and uses.

Herbarium specimens from the 19th-early 20th centuries come from Afghanistan, northwest Pakistan, Turkestan (Uzbekistan, Tajikistan, Kyrgyzstan, Xīnjiāng Region in China), and Iran. These plant were cultivated for sieved hashīsh (nasha, charas) and sometimes for seed oil.

Comments.

Vavilov (1926) characterized afghanica as "a morphological link between the wild and the cultivated races of hemp." However, evidence in Vavilov and Bukinich (1929) suggests a domesticated phenotype (argued in Suppl. material 1: SF.6). Small and Cronquist (1976) treated afghanica as a domesticate, synonymized under C. sativa subsp. indica var. indica . Small (2018) commented, "The characteristics of indica type marijuana are highly consistent with those of an advanced cultigen. Like modern oilseed cultivars, they are short and compact, an architecture reducing diversion of energy into stem production and increasing harvest index for the desired product (inflorescence). Even the foliage (with very large, wide leaflets) is consistent with the trend described earlier of advanced cultigens often manifesting larger leaves than their wild and more primitive cultivated relatives. When indica type strains are allowed to set seed (they are normally harvested for flowering material) the infructescences are very dense, preventing most of the seeds from falling away and being distributed naturally - another indication of considerable domestication." The prominent sugar leaves in the inflorescence may be another indication of domestication, as these likely increase photosynthate production very close to the developing flowers and their perigonal bracts.

Figures

Figure 5. Type specimens of C. sativa subsp. indica var. afghanica. Neotype on left (a), epitype on right (b).