Artemisia sect. Absinthium in Flora of China @ efloras.org

1. Artemisia sect. Absinthium (Miller) Candolle in Candolle & Lamarck, Fl. Franç. 4: 189. 1805.

莳萝蒿组 shi luo hao zu

Absinthium Miller, Gard. Dict. Abr., ed. 4. 1754; Absynthium G. Gaertner, B. Meyer & Scherbius.

Shrubs, subshrubs, or annual, biennial, or perennial herbs, tomentose or puberulent, rarely arachnoid, without glandular or viscid hairs (sessile glands often present). Leaves 1-3-pinnatisect; lobes or lobules linear or filiform, serrate. Capitula globose or subglobose. Phyllary margin scarious. Receptacle pubescent or chaffy, hairs sometimes deciduous. Marginal florets (2-)4-30, sometimes in 2 series and up to 70; corolla vasiform or narrowly conical, (2-)4-toothed. Disk florets (8-)20-120, bisexual; ovaries well developed; style ca. as long as or longer than corolla, branches divergent, recurved at apex.

About 50 species: N Hemisphere, mostly in Asia and Europe, five species in North America, a few species in Africa and Central and South America; 23 species (three endemic) in China.

Most species contain monoterpenoids.

1 Annual or biennial herbs; main root solitary, vertical, tapered or ± fusiform; basal leaves (including petiole) usually less than 8 cm (2)

+ Perennial herbs, subshrubs, or shrubs; roots several, not fusiform (if biennials with single fusiform root then basal leaves 11-18 cm); basal leaves usually more than 8 cm (7)

2 (1) Synflorescence a simple erect terminal raceme; capitula 5-10(-15) mm in diam. 1 A. macrocephala

+ Synflorescence a panicle with spreading lateral branches; capitula 1.5-4(-6) mm in diam (3)

3 (2) Capitula 3-6 mm in diam.; marginal female florets 5-30, bisexual florets 30-120 (4)

+ Capitula 1.5-3(-4) mm in diam.; marginal female florets 3-6, bisexual florets 18-28 (5)

4 (3) Plants 50-150 cm tall; middle stem leaf blades 4-8(-13) × 3-6(-15) cm; female florets 20-30, often in double series, bisexual florets 80-120. 2 A. sieversiana

+ Plants 25-40 cm tall; middle stem leaf blades 1.5-2 × 1-1.5 cm; female florets 5-20 in single series, bisexual florets 30-50. 22 A. succulentoides

5 (3) Basal leaf blades 8-15 × 8-15 cm. 19 A. nakaii

+ Basal leaf blades 3-4.5(-5) × 2-4 cm (6)

6 (5) Capitula 2-3(-4) mm in diam.; bisexual florets 18-28. 20 A. anethifolia

+ Capitula 1.5-2(-2.5) mm in diam.; bisexual florets 8-16. 21 A. anethoides

7 (1) Disk florets 8-20 (8)

+ Disk florets 20-80 (11)

8 (7) Plants 15-25(-30) cm tall, densely gray or yellowish tomentose. 16 A. younghusbandii

+ Plants 25-80 cm tall, gray or yellowish arachnoid tomentose or silky pubescent, lower parts sometimes glabrescent (9)

9 (8) Middle stem leaf blades 3-5 × 3-5 cm; marginal female florets 2-5. 18 A. fauriei

+ Middle stem leaf blades 0.5-2 × 0.8-2.8 cm; marginal female florets 4-10 (10)

10 (9) Ultimate leaf lobules narrowly spatulate, linear, or linear-oblanceolate, 1-3 × 0.5-1.5 mm. 9 A. xerophytica

+ Ultimate leaf lobules elliptic-oblanceolate or elliptic-lanceolate, 6-12 × 1-1.5 mm. 10 A. rutifolia

11 (7) Leaf blade entire or with apex crenately 3-5-lobed. 12 A. lagocephala

+ Leaf blade 1-3-pinnatisect (12)

12 (11) Capitula 2-4(-5) mm in diam (13)

+ Capitula 4-10 mm in diam (16)

13 (12) Basal to middle stem leaves with petiole 2-12 cm; plants 60-150 cm tall. 5 A. absinthium

+ Basal to middle stem leaves sessile or with petiole to 2 cm; plants 20-70 cm tall (14)

14 (13) Middle stem leaves sessile, gland-dotted. 11 A. obtusiloba

+ Middle stem leaves with petiole 5-20 mm, not gland-dotted (15)

15 (14) Bisexual florets 20-30; perennial herbs or occasionally subshrubs with slender rootstock; plants densely yellowish or pale yellow sericeous. 6 A. frigida

+ Bisexual florets 35-50; subshrubs with a thick woody rhizome ca. 1 cm or more in diam.; plants arachnoid puberulent, glabrescent. 23 A. persica

16 (12) Plants densely yellowish to yellow sericeous-tomentose; corolla with multicellular hairs; basal leaves 5-10 cm, with 7-13 pairs of lateral segments. 17 A. stracheyi

+ Plants pubescent or glabrescent; corolla glabrous; basal leaves less than 5 cm, with 3-7 pairs of lateral segments, or leaves 3-cleft (17)

17 (16) Plants 10-20 cm tall (18)

+ Plants 20-70 cm tall (20)

18 (17) Middle stem leaves with petiole 2-3 cm, blade pubescent, later glabrescent, greenish, abaxially gland-dotted; phyllary margin black scarious. 13 A. disjuncta

+ Middle stem leaves with petiole 0.4-1 cm, blade densely gray or yellowish tomentose, or glabrescent, abaxially not gland-dotted; phyllary margin brown scarious (19)

19 (18) Perennial herbs; middle stem leaves with (3 or)4(or 5) pairs of segments, segments serrate or with lobules 2-8 × 0.6-1 mm, pubescent, soon glabrescent; phyllaries with brown scarious margin, glabrescent. 14 A. niitakayamensis

+ Caespitose dwarf subshrubs; middle stem leaves with 2(or 3) pairs of segments, 3-5-lobulate, lobules 1-2 × 0.5-1 mm; leaves and phyllaries densely yellowish or gray tomentose. 15 A. minor

20 (17) Middle stem leaves (1-)1.5-4 cm, densely yellowish or white sericeous-tomentulose; middle lobes 1.5-4 mm wide (21)

+ Middle stem leaves 0.8-1.5 cm, tomentose, pubescent, or glabrescent; middle lobe less than 1 mm wide (22)

21 (20) Plants 40-60(-75) cm tall; middle stem leaves elliptic or ovate; phyllary with narrow, white scarious margin. 3 A. sericea

+ Plants 20-40(-50) cm tall; middle stem leaves suborbicular or orbicular-reniform; phyllary with wide, brown scarious margin. 4 A. aschurbajewii

22 (20) Middle stem leaves with 5-7 pairs of segments, distal lobes pinnatisect or 3-lobulate, proximally not lobed, pubescent, glabrescent; phyllaries pubescent. 8 A. rupestris

+ Middle stem leaves with 2 or 3(-5) pairs of segments, segments parted or lobulate; leaves and phyllaries yellowish sericeous-tomentose or pubescent or glabrescent. 7 A. argyrophylla

List of lower taxa