Echiostachys incanus (Thunb.) Levyns

Velani, N., Boatwright, J. S., Magee, A. R. & Manning, J. C., 2023, Taxonomy of the small southern African endemic genus Echiostachys Levyns (Boraginaceae: Boraginoideae), South African Journal of Botany 156, pp. 244-256 : 246-252

2. Echiostachys incanus (Thunb.) Levyns

in J. Linn. Soc., Bot. 49: 446 (1934). Echium incanum Thunb ., Prod. Pl. Cap. 1: 33 (1794); Thunberg, Fl. Cap.: 164 (1823). Type: South Africa, Western Cape, ‘ Cape of Good Hope’ [Swartlandiae arenosis], Thunberg s.n. ( UPS-THUNB4102 , lecto., designated by Nordenstam and Buys in Taxon 60: 1191 (2011); LD1258404 -image!, MEL2433464 -image!, SBT12951 , isolecto.).

Lobostemon splendens H.Buek in Linnaea 11: 146 (1837); C.H. Wright in F1. Cap. 4(2): 40 (1904). Echium splendens (H.Buek.) DC. & A.DC ., Prodr. 10: 15 (1846). Type: South Africa, Western Cape, Clanwilliam (3218): ‘prope Brakfontein’ ( Clanwilliam ) (− BB), Aug.-Sept., Ecklon & Zeyher ( MEL238964 -lecto.-image!, designated here; G190392 -image!, HAL115139 -image!, HBG503003 & 503004 - images!, SAM18645 !, isolecto.). Note: The MEL duplicate is selected as lectotype as it is a fine collection and bears the inscription ‘ Lobostemon splendens nov. sp.’ in Lehmann’ s handwriting. Duplicates from his herbarium are known to have been used by Buek ( Buys and Nordenstam, 2009).

Lobostemon virdi-argenteus H.Buek in Linnaea 11: 144 (1837); C.H. Wright in F1. Cap. 4(2): 41 (1904). Echium viridi-argenteum (H.Buek.) DC. & A.DC ., Prodr. 10: 13 (1846). Type: South Africa, Western Cape, Clanwilliam (3218): ‘ad radices Piquet-berge [Piketberg]’ (− DC), Oct., Ecklon & Zeyher (G190390, lecto-image!, designated here ). Note: We designated the G material as lectotype as it is the only original material that we have been able to locate. Duplicates of other Lobostemon species described by Buek (1837) are available online [https://plants. jstor.org accessed Nov 2022] but only this one of L. viridi-argenteus .

[ Echium spicatum sensu L.f., Suppl. Pl.: 132 (1782), Thunb., Fl. Cap.: 165 (1823) et Candolle, Prodr. 10: 14 (1846), non Burm. f. (1768)]

[ Lobostemon spicatus sensu C.H.Wright in Fl. Cap. 4(2): 41 (1904), non (Burm.f.) H. Buek (1837)].

Note: Linnaeus (1782) applied the name Echium spicatum to a collection consistent with E. incanum in the Linnean Herbarium (LINN191.6). Levyns (1934) interpreted this as independent publication of the later homonym E. spicatum L.f., (non Burm.f .) and therefore treated E. spicatum ‘L.f .’ as a synonym of E. incanum . This interpretation is not justified as there is no reason to doubt that Linnaeus (1782) was merely misapplying Burmann’ s name, as was explained by Nordenstam and Buys (2011). Wright (1904) followed Linnaeus (1782) in misapplying the name E. spicatum to E. incanum . The correct application of the name E. spicatum was established by Levyns (1934).

Common name: Common Boragebrush

Caespitose perennial herbs; rootstock cylindrical-tapering. Radical eaves, ± 7 to 12, sub-erect, linear-oblanceolate, 130 − 230 (− 260) X 6 − 20 mm, acute or attenuate, narrowed and petiole-like below, abaxial and adaxial surfaces adpressed strigose-villous with a mix of long and short hairs ± 1 − 2 mm long, trichomes simple or pustular, white; petiole-like base densely sericeous with simple hairs. Flowering stems arising laterally to leaf tuft, flexed outwards at base then erect, 200 − 400 mm long, villous with patent hairs 1 − 2 mm long, densely sericeous at base; cauline leaves sub-erect, smaller than radicalleaves, linear-oblanceolate, acute-attenuate, strigose-villous. In fl orescence a dense cylindrical pseudo-spike of numerous 1 to 3(4)- flowered cymules, 25 − 150 X (15 −)20 − 30 mm; pedicels 2 − 3 mm long, strigose-pilose; bracts linear-oblanceolate, 2 − 10 mm long, lowermost bracts somewhat leaf-like. Calyx slightly accrescent to 9 mm long in fruit, sepals linear-oblanceolate, 3 − 5 mm long, obtuse, densely sericeous. Corolla funnel-shaped, 6 − 9 mm long, cream-coloured or white; tube 4 − 7 mm long, outer surface very sparsely villous mainly opposite filament insertion, inner surface bearded between filament bases, lobes ovate, ± 2 mm long, central veins sparsely hairy. Stamens inserted 2 − 4 mm from base of corolla tube, subequal or one longer than the rest, ± 10 mm long, longest stamen exserted ± 4 mm beyond tube, shorter exserted ± 2 mm; filaments bearded at the base in a brush like tuft ± 2 mm long; anthers ± 0.5 mm long. Style 10 − 13 mm long, exserted ± 4 mm beyond the tube, sparsely villous in lower two thirds. Nutlets ellipsoid-apiculate, inner surface with median ridge, 3 − 4 X 1.5 − 2.5 mm, rugose-tuberculate but less so towards base, echinulate, tubercles tipped with 1 or 2 longer stiff glassy hairs, pale gray. Flowering time: Aug − Oct ( Figs. 1B, C and 4 ).

Distribution and ecology: Echiostachys incanus is restricted to the south-western parts of Western Cape, South Africa, ranging from the lower Olifants River Valley north of Citrusdal along the western foothills of the coastal mountains from Piketberg southwards to the flats at the base of the Hottentots-Holland Mountains at Gordon’ s Bay, extending slightly inland along the Upper Breede River Valley to near Worcester and eastwards to Greyton at the western end of the Riviersonderend Mountains [there are historical records from further east in the form of a single collection each from Elim (Anon s.n. SAM 18,647) and Swellendam (Mund SAM 18,646) respectively but both date from the nineteenth century and the species has not been collected there since] ( Fig. 5 ); on seasonally wet, gravelly or loamy flats from near sea level to 800 m a.s.l.

Diagnosis and relationships: Echiostachys incanus is the most widespread and commonly collected species in the genus and is usually readily identified by its whitish flowers with corolla 6 − 9 mm long and the ± markedly acute or attenuate radical leaves, the bases of which are conspicuously covered in dense silky hairs. These silky hairs at the base of the radical leaves are also characteristic of E. spicatus from the coastal forelands but that species has significantly larger flowers, ± 12 mm long. Florally, E. incanus is unique in the genus in having the filament hairs tightly bunched into a brush-like tuft at the base of the filaments, rather than a more extended beard as in E. ecklonianus and E. spicatus . This difference in filament hairs, combined with differences in corolla color and radical leaf apex serve to separate E. incanus from E. ecklonianus , which has similarly small flowers, 6 − 8 mm long but pink or mauve to blue, and mostly obtuse radical leaves that lack the dense silky vestiture at the base.

The markedly reticulate-tuberculate seeds of E. incanus may also be distinctive, as seeds in the other two species are evidently obscurely striate or almost smooth but further observations are needed to confirm this.

Additional specimens examined

South Africa. WESTERN CAPE: 3218 (Clanwilliam): Clanwilliam (− BB), without date, Zeyher s.n. (SAM); Olifant’ s River Valley , 10 miles [16 km] north of Citrusdal (− DB), Sep 1945, Levyns 57,915 (SAM); 5 miles [8 km] north of Citrusdal (− DC), 1 Sep 1945, Compton 17,125 (NGB); Piketberg, Witwater Moravian Mission, slope above the Mission (− DC), 11 Oct 2009, Koopman 4078 (NGB); Piketberg (− DC), Oct 1895, Bolus 13,613 (BOL). 3318 (Cape Town): Porterville (− BB), September 1960, Loubser 1071 (NBG); 19 Oct 1964, Kellerman 18 (NGB); Riverlands Nature Reserve (− DA), 26 Aug 1992, Kurzweil 1689 (NBG); Riverlands Nature Reserve , central area near track (− BC), 13 Sep 2009, Helme 6284 (NBG); Botterberg (− DA), 19 Sep 1943, Wasserfall 418 (NGB); Dassenberg , Kalbaskraal , (− DA), Apr 1965, Gouws 208 (NBG); between Durbanville and Wellington (− DC), Oct 1929, Levyns 2525 (BOL); Durbanville (− DC), 30 Sep 1966, Compton 16,036 (NBG); Durbanville , D’ Urbanvale Estate, Uitkamp wetlands (− DC), 12 Dec 2008, Cowell, Stoll & Pekeur 3886 (NBG); 12 Sep 2013, Helme 8057 (NBG); Kraaifontein (− DC), 1 Sep 1938, Acocks & Hafstr ¨ om 1297 (PRE); Eersterivier, Penhill Estate, Greg Avenue, shale band (− DD), 26 Sep 1979, Raitt 424 (NBG); Stellenbosch, Van der Stel (− DD), Sep 1926, Smith 3226 (PRE); Stellenbosch Flats (− DD), Sep 1927, Markotter 8565 (NGB); Uitkyk (− DD), Nov1883, MacOwan 4116 (SAM); 1928, Gillett 1823 (NBG); Stellenbosch (− DD), Ecklon 50,973 (SAM); Duthie 676 (SAM); Elsenberg (− DD), 18 Sep 1926, Grant 2153 (PRE). 3319 (Worcester): ± 6 km N of Gouda, Bonne Esperance 83, west of Roodezandberg (− AA), 30 Sep 2010, Helme 6793 (NBG); near Hermon on farm Bartholomeusklip, flats near stream before homestead (− AC), 13 Sep 2001, Trinder-Smith 278 (BOL); Hex River Valley, Oct 1895 (− BC), Marloth 6193 (PRE); Wellington (− CA), 13 Sep 1941, Compton 11,629 (NBG); between Worcester and Villiersdorp (− CB), 1 Oct 1951, Compton 22,919 (NBG); Botha’ s Halt [ Botha ], (− CB), 5 Aug 1959, Van Breda 617 (PRE); hills southeast of the Greater Brandvlei Dam (south of Worcester) (− CB), Sep 2014, Le Roux 1182 (NBG); 15 km NW of Worcester, Bobbejaansriver Valley east of Rondekop (− CB), 16 Nov 2016, Helme 8867 (NBG); Paarl east, SE of Newton, north of old sewage ponds, Kykuit , erf 961 (− DB), 4 Nov 2008, Helme 5768 (NBG); clay flats near Paarl, north of town (− DB), 24 Sep 1974 Goldblatt 2743 (NBG, PRE); Paarl , railway, (− DB), without date, Drege 50,974 (SAM); Hercules Pillar (− DD), 16 Sep 1942, Compton 13,654 (NGB). 3320 (Montagu): Swellendam (− CD), without date, Mund SAM 18,646 (SAM). 3418 (Simonstown): Cape Flats , Wynberg (− AB), 17 Sep 1935, Letty 276 (PRE); Faure (− BA), 13 Sep 1942, Barker 1665 (NBG); 16 Sep 1946, Compton 15,987 (NBG); Faure, Vergenoegd Farm Extension -Portion 653 − 15 (− BA), 20 Oct 2007, Boucher 7450 (NBG); Kuilsriver, Faure , Vergenoegd 653, 0.7 km N of N2, 0 .4 km E of R310 (− BA), 6 Oct 2005, Helme 3659 (NBG); Somerset West (− BB), 4 Sep 1942, Parker 3716 (BOL); 1 Sep 1953, Parker 4906 (NBG); Firgrove (− BB), 3 Sep 1942, Compton 13,456 (NBG); farm near Somerset West (− BC), Oct 1928, Levyns 2545 (BOL); Somerset West (− BB), clay sandy places in flats, 2 Oct 1921, Nel 1267 (NBG); SW of Somerset West , (− BB), 9 Sep 1974, Mauve 4950 (PRE); Gordon’ s Bay, flats in Gustrouw area , vacant erf at top of Lemoenboom (− BB), 10 Sep 2003, Helme 2822 (NBG); Gordon’ s Bay Flats, open plot next to Seascape Rd (− BB), 3 Aug 1993, Buys 430 (NBG); between Gordon’ s Bay and Sir Lowry’ s Pass (− BB), 6 Sep 1931, Levyns 3210 (BOL); Gordon’ s Bay Flats (− BB), Sep 1921, Bolus 9945 (BOL); Strand, at R44 road, between Octopus Road and Janbruin Road (− BB), 26 Sep 2004, Mucina 260,904/19 (NBG); Strand, erf 14,335, Weltevreden area, just west of High School (− BB), 31 Aug 2009, Helme 6420 (NGB); Strand, Harmony Reserve (− BB), 27 Aug 2000, Runnalls 1032 (NBG). 3419 (Caledon): Papenvlei [ Elim ] (− DB), Sep 1896, Anon s.n. SAM 18,647 (SAM).

Imprecise locality: Cape, Pappe 18,645 (SAM).

Figures

Fig. 1. Echiostachys species. A. E. ecklonianus. Western Cape, Bredasdorp, Sandberg Fynbos Reserve. B, C. E. incanus. Western Cape, Wellington, Elandsberg Nature Reserve. D, E. E. spicatus. Western Cape, Langebaan, Elandsfontein. Photographs:A, Rupert Kopman;B, C, John Manning; D,E, Nick Helme .

Fig. 4. Echiostachys incanus. Western Cape, Elim, Anon s.n. SAM 18647 (SAM). A, whole plant; B, detached flower; C, corolla opened out; D, single stamen showing bearded filament base. Scale bar: A = 20 mm; B̅D = 2.5 mm.Artist: N.Velani.

Fig. 5. Distribution of Echiostachys incanus.