Phymaspermum, Less.

Ruiters, Ashton K., Tilney, Patricia M., Wyk, Ben-Erik Van & Magee, Anthony R., 2016, Taxonomy of the Genus Phymaspermum (Asteraceae, Anthemideae), Systematic Botany (Basel, Switzerland) 41 (2), pp. 430-456 : 435-436

PHYMASPERMUM Less. , Syn. Gen. Compos.: 253 (1832); DC., Prodr. 6: 44 (1838); Harv. in Harv. and Sond., Fl. Cap. 3: 160 (1864); Benth. and Hook. f. ex B.D. Jacks., Gen. pl. 2 (1): 422 (1873); Källersjö in Nord. J. Bot. 5(6): 535 (1986); B.D. Jacks., Index Kew. 1: 37 (1893); K. Bremer and Humphries in Bull. Nat. Hist. Mus. Lond. (Bot.) 23(2): 94 (1993); Retief and P. P. J. Herman, Pl. N. Prov. S. Afr.: 329 (1997); Goldblatt and J. C. Manning, Cape Pl.: 352 (2000); Germish. and N. L. Mey., Pl. S. Afr.: 273 (2003); Klopper et al. Checklist of the flowering plants of Sub-Saharan Africa: 147 (2006); Germish. et al. Checklist S. African Pl.: 243 (2006); Kadereit and C. Jeffrey in Fam. Gen. Vasc. Pl. [Kubitzki] 8: 356 (2007).

— TYPE: Phymaspermum leptophyllum (DC.) Benth. & Hook. f. ex B.D. Jacks. (Proposed conserved type, Magee et al. 2013)

Adenachaena DC. , Prodr. 6: 49 (1838); Harv. in Harv. and Sond., Fl. Cap. 3: 160 (1864); B.D. Jacks, Index Kew. 1: 37 (1893).

— TYPE: Adenachaena leptophylla DC. ≡ Phymaspermum leptophyllum (DC.) Benth. & Hook. f. ex B.D. Jacks.

Brachymeris E. Mey. ex. DC. , Prodr. 6: 76 (1838); Harv. in Harv. and Sond., Fl. Cap. 3: 163 (1865); Hutch. in Bull. Misc. Inform. Kew 1916: 171 (1917); Källersjö in Nord. J. Bot. 5(6): 535 (1986).

— TYPE: Brachymeris scoparia E. Mey. ex. DC. ≡ Phymaspermum scoparium (E. Mey. ex. DC.) Källersjö

Oligoglossa DC. , Prodr. 6: 76 (1838); B.D. Jacks, Index Kew. 1: 339 (1893) Iocaste E. Mey ex Harv. in Harv. and Sond., Fl. Cap. 3: 160 (1865).

— TYPE: Oligoglossa acicularis E. Mey. ex. DC. ≡ Phymaspermum aciculare (E. Mey. ex. DC.) Benth. and Hook. f. ex. B.D. Jacks.

Evergreen, single- to multistemmed, very sparsely to densely leafy, shrubs or shrublets, 0.2–2.0 m high. Stems unbranched to much-branched; branches erect or spreading, rarely spinetipped, striate, glabrous to densely matted; fascicles usually present in leaf axils, sometimes becoming woolly (in P. acerosum and P. woodii ). Leaves sessile, alternate or rarely opposite ( P. oppositifolium ), very sparsely to closely imbricate, appressed to spreading, 1.0–40.0 × 0.2–3.0 mm, linear to spathulate, entire to pinnatifid, margins involute to revolute, sometimes narrowed into petiole-like base with secondary basal lobes, glabrous to villous, bony, leathery or fleshy; basal swelling continuous with stem ribs present; lobes 0–9, 0.2–24.0 × 0.5–1.5 mm, linear, mucronate to attenuate. Capitula homogamous or heterogamous, radiate, disciform or discoid, terminal or on very short axillary shoots, solitary, with 0–3 additional capitula from leaf axils below or in few- to many-headed (3 to>100), simple or compound corymbs, pedunculate or rarely subsessile; peduncles 1.0–95.0 mm long, glabrous to densely matted. Involucre cylindrical or urceolate to campanulate or hemispherical, sometimes tapering at the base; involucral bracts 3- to 7-seriate, loosely or tightly arranged, 1.0–7.0 mm long, ovate to linear, obtuse to attenuate, margins and apices scarious (bracts entirely scarious in P. appressum and P. oppositifolium ), inner bracts with membranous apices 0.3–2.5 mm long, glabrous to densely villous, green to dark brown, purple, sometimes with brown margins, median resin canals present. Receptacle flat to convex, alveolate, paleate; paleae in marginal series (rarely rudimentary inner paleae present), 2.6–6.3 mm long, linear to obovate, apices obtuse to attenuate, entirely scarious or margins and apices scarious. Ray florets (when present) 3–22, pistillate; tube 1.0– 4.2 mm long, sessile glandular trichomes present; limb 3.0–12.0 × 1.8–4.3 mm, ovate to obovate, usually apically 3-dentate, rarely 2-dentate or entire, white to purple. Filiform florets (only in P. athanasioides ) ± 20, pistillate; corolla 2.3–3.0 mm long, yellow, with sessile glandular trichomes, zygomorpic; adaxial lobes 2, abaxial lamina 3-dentate, without resin canals. Disc florets 3 to> 100, bisexual, without resin canals (except sometimes in P. acerosum ); corolla 1.6–4.0 mm long, with sessile glandular trichomes, zygomorphic; glabrous or rarely pilose, yellow to purple; tube 0.7–2.6 mm long; limb 0.5–1.8 mm long (excluding lobes), very narrowly to broadly campanulate, 5-lobed; lobes erect to spreading, 0.3–1.0 mm long, narrowly to broadly triangular or triangular ovate. Anthers 2.0– 4.3 mm long (including apical appendage), sagittate at base; apical appendages lanceolate to rounded. Style 1.7–4.0 mm long (excluding the two terminally stigmatic branches), terete with thickened base; branches 0.1–1.9 mm long, truncate, with dorsal papillae. Cypselas 1.6–3.5 ×0.5–1.0 mm, oblong to broadly obovoid, shortly papillate, apical rim absent or thickened to membranous, conspicuously or inconspicuously (in P. leptophyllum ) 10- to14-ribbed, stalked glandular trichomes present or rarely absent, usually mucilaginous, discontinuous resin canals in ribs rarely present (in P. acerosum , P. comptonii , and P. pinnatifidum ).

Diagnostic Characters — Phymaspermum shares the papillose, many ribbed (≥ 10) cypselas with Eumorphia and Gymnopentzia but can be distinguished by the alternate leaves (except in one species, P. oppositifolium ) and the presence of unique stalked myxogenic trichomes on the cypselas (subsequently lost in two species, P. acerosum and P. pinnatifidum ). It can be further distinguished from Eumorphia by the absence of inner paleae (inner paleae present in Eumorphia ) and from Gymnopentzia by the shortly papillose cypselas (long papillate cypselas in Gymnopentzia ).

Distribution and Ecology — Phymaspermum is largely restricted to southern Africa, with one species extending into Zimbabwe. Six of the species are endemic to the Greater Cape Floristic region.

KEY TO THE SPECIES OF PHYMASPERMUM

1. Capitula in prominent corymbs......................................................................................... 2

2. Capitula heterogamous with filiform outer florets; primary leaves mostly entire, some 2- or 3-fid........................ 12. P. athanasioides

2. Capitula homogamous; primary leaves mostly trifid to pinnate................................................................ 3

3. Involucral bracts closely appressed, deltoid to ovate, dorsal surface flat; fruits without resin canals.................................... 4

4. Leaf lobes ≤ 0.5 mm wide, usually sparsely villous; involucre apically constricted, bracts with indistinct to light brown margins; restricted to KwaZulu-Natal and Eastern Cape ..................................................... 13. P. woodii

4. Leaf lobes ≥ 1 mm wide, usually silvery sericeous; involucre apically spreading, bracts with prominent dark brown margins; restricted to Limpopo and Mpumalanga ................................................... 14. P. argenteum

3. Involucral bracts loosely appressed, narrowly ovate to lanceolate, dorsal surface ridged; fruits with resin canals......................... 5

5. Ovary and fruit with a prominent membranous crown; plants less than 0.5 m tall, stems thin and herbaceous; spring flowering...................................................................................... 16. P. pinnatifidum

5. Ovary and fruit at most apically dentate; plants more than 0.5 m tall, stems stout and woody; autumn to winter flowering................................................................................................... 6

6. Involucre campanulate, bracts ± equal, innermost with prominent rounded scarious appendages; fruits with stalked trichomes; leaves usually silvery sericeous................................................... 15. P. comptonii

6. Involucre cylindrical to narrowly campanulate (rarely campanulate), bracts clearly unequal, innermost without rounded scarious appendages; fruits without stalked trichomes; leaves glabrescent to villous..................... 17. P. acerosum

1. Capitula solitary, sometimes with 1–5 additional capitula from leaf axils below................................................... 7

7. Capitula discoid (sometimes radiate in P. aciculare but then ray florets scanty, up to four, with small limb, less than 5 mm long)............................................................................................... 8

8. Capitula subsessile, axillary, peduncle becoming spinescent; floret limb hairy........................................... 1. P. scoparium

8. Capitula prominently pedunculate, terminal, not spinescent; floret limb glabrous.................................................. 9

9. Stem and leaves glabrous; capitula obconical, <6 mm wide, with 3–5 additional capitula from leaf axils below................. 9. P. aciculare

9. Stem and leaves pubescent to sericeous; capitula cyathiform (cup-shaped) to hemispherical,> 5 mm wide, solitary or with up to 2 additional capitula from the leaf axils below......................................................... 10

10. Stem and leaves silvery villous or hispid; leaves 2–10 mm long; fruits ≤ 4 mm long..................................... 10. P. erubescens

10. Stem and leaves densely bronze villous; leaves 9–18 mm long; fruits> 4 mm long......................................... 11. P. peglerae

7. Capitula radiate (rays more than four and limb usually more than 5 mm long).................................................... 11

11. Leaves strongly appressed; involucral bracts largely scarious, with obscure resin canals............................................. 12

12. Leaves alternate; involucral bracts ovate........................................................................ 7. P. appressum

12. Leaves opposite; involucral bracts lanceolate to oblong........................................................ 8. P. oppositifolium

11. Leaves erect to spreading; involucral bracts herbaceous to bony with only narrow scarious margins and apices, with prominent resin canals.......................................................................................... 13

13. Compact, closely branched shrublets, ≤0.3 (0.4) m tall, capitula with <8 ray florets..................................... 2. P. parvifolium

13. Straggly, openly branched shrubs, ≥ 0.5 m tall, capitula with ≥8 ray florets....................................................... 14

14. Leaves silvery sericeous, spathulate to trifid, flat; involucral bracts ovate to narrowly ovate.......................................... 15

15. Leaves regularly trifid along the entire stem; innermost involucral bracts with broad scarious appendages; floret tube without hairs......................................................................... 4. P. trifidum

15. Leaves entire, spathulate (some becoming trifid towards the peduncle); innermost involucral bracts without broad scarious appendages; floret tube usually prominently hairy........................................ 3. P. thymelaeoides

14. Leaves glabrous to sparsely pubescent, green, linear, subterete; involucral bracts lanceolate to oblong.................................. 16

16. Stems not longitudinally white-striped, hairs scattered along stem; leaves not sparse or caducous, ±1.0–2.0 mm wide; peduncles not becoming spinescent, fruits with indistinct ribs and myxogenic trichomes apparently sessile............................................................................. 5. P. leptophyllum

16. Stems longitudinally white-striped, densely white woolly between ribs; leaves sparse, caducous, ± 0.5 mm wide; peduncles often become spinescent; fruits with distinct ribs and obviously stalked myxogenic trichomes............................................................................... 6. P. aphyllum