Physotrichia longiradiatum H. Wolff (1912: 273)

Winter, Pieter J. D., Tilney, Patricia M. & Wyk, Ben-Erik Van, 2017, Clarification of the concept of Aframmi (Heteromorpheae, Apiaceae) and a new monotypic genus, Normantha, Phytotaxa 298 (1), pp. 71-76 : 73-75

Physotrichia longiradiatum H. Wolff (1912: 273)

Aframmi longiradiatum (H.Wolff) Cannon (1978: 587) , synon. nov. [only as regards the type specimen] Type: D. R. Congo, Oberes Katanga, Kasanga fl., zwischen hohem grase, 23/3/1908, Kassner 2666 (holotype, B†, photo in BM!; possibly isotypes Kassner 2667, BM!, photo in K!; BR!; K!). Note: Kassner 2666 and 2667 are almost certainly part of the same collection – the label and label information are the same except that the 7 of Kassner 2667 in the Berlin specimen appears to have been changed to 6. The BM and K specimens could therefore be interpreted as isotypes. This species is illustrated in Van Wyk et al. (2013: 258).

The third taxon from the border region between Zambia and Tanzania, which Cannon (1978) confused with Aframmi longiradiatum , has non-amplexicaul, evaginate leaf bases, very narrow ultimate leaf segments that are usually falcate, and narrowly linear or acicular involucral bracts ( Fig. 1 ). On closer examination, additional collections from Angola, incorrectly identified by Norman (1933) as Aframmi angolense , also clearly belong to this taxon. Townsend (1989) regrettably omitted the species from his treatment for the Flora of Tropical East Africa. It has fruits with large rib oil ducts ( Fig. 2A 3) and scattered druse crystals throughout the mesocarp, as well as regular vittae and a woody habit, the combination of which is characteristic of several genera of the tribe Heteromorpheae M.F.Watson & S.R.Downie in Downie et al. (2000: 289).

Since the type species of Aframmi is a species of Heteromorpha and Aframmi longiradiatum is here treated as a Physotrichia , the third remaining element is left without a name or even a generic placement. It is likely that its affinities lie within the tribe Heteromorpheae , based on woodiness, long, slender rays ( Fig. 1 ) and prominent rib oil ducts ( Fig. 2A 3) which also characterise some other genera of that tribe. It differs from all other genera in the tribe in the much divided filiform leaves and leaf segments. The woody habit is very unusual for Apiaceae . The extended woody, vegetative axis was no doubt the basis for confusion with Carum angolense , and the combination of this character with the presence of vittae appears to be restricted to tribe Heteromorpheae , in the genera Anginon Rafinesque (1840: 56) , Cannaboides B-E.van Wyk in Van Wyk et al. (1999: 740), Heteromorpha , Polemannia Eckl. & Zeyh. (1837: 347) , Pseudocannaboides B-E.van Wyk in Van Wyk et al. (1999: 742), Pseudocarum C. Norman (1924: 333) and Tana B- E.van Wyk in Van Wyk et al. (1999: 743). Of these, the inflorescence architecture (i.e., long, slender rays and pedicels), fruit shape and prominent rib oil ducts agree most closely with that of Pseudocarum .

We considered alternative treatments to avoid creating another monotypic genus of African Apiaceae , but we concluded that the new species is not similar enough to Pseudocarum or any other genus to warrant its description in an existing genus. A third option would have been to submit a proposal to conserve the name Aframmi for this entity, with a conserved type but this approach would no doubt serve only to complicate future interpretation even further. As such we here describe the taxon as a new monotypic genus. A key to the identification of the new genus can be found in Van Wyk et al. (2013).

Normantha P.J.D.Winter & B-E.van Wyk, gen. nov. Similar to Pseudocarum and Dracosciadium Hilliard & Burtt (1986: 220) in the slender, filiform rays, the obovoid homomericarpic fruits and the large rib oil ducts but differs in the filiform leaf lobes, the longer, filiform involucral bracts and the erect, woody stems (stems climbing and woody in Pseudocarum , acaulescent, fleshy and rhizomatous in Dracosciadium ). It differs from Heteromorpha in the homomorphic mericarps, the filiform leaf segments and filiform involucral bracts. Type species: Normantha filiformis P.J.D.Winter.

Erect, glabrous suffrutex, 0.75–1.00 m tall, perennial, rootstock woody. Stems woody, ascending, with leaves regularly spaced along most of their length. Leaves 2–3-pinnatifid, deciduous?, (20–) 30–60 (–100) mm long; leaflets 10–30 mm long. Leaf bases non-sheathing. Petioles short, less than 10 mm long, subterete, filiform. Leaflets linear-acicular, entire, filiform, incision sometimes decursive. Umbels terminal only, or both terminal and lateral. Terminal umbels somewhat irregular, with long, ± 10 wiry, wide-spreading rays, 30 to 100 mm long. Bracts several, irregular, filiform, simple or pinnatifid, 8–24 mm long; bracteoles filiform, subulate, ± 2 mm long. Pedicels (raylets) rather long and wiry, elongating with fruit set, 10–22 mm long. Umbellules of 6 to 15 flowers. Calyx teeth minute, broadly triangular; petals yellowish-green, with an inflexed apex. Stylopodia low-conical, disk margin with regular indentations; styles short, divergent, stigmatic surface slightly clubbed. Fruits homomericarpic, obovoid, ± 5 x 2 mm, mericarps isodiametric; ribs 5, equal, rounded. Vittae well developed, 1 in each vallecula and 2 in the commissural face. Rib oil ducts large. Amphiseminal druse crystals present. Seeds pentagonal in section, very slightly sulcate on the commissural side. ( Figs. 1 & 2 ).

Normantha filiformis P.J.D.Winter , sp. nov. (see diagnosis and description above). Type: Zambia, Kalambo Falls, 29/3/1955, Richards 5198 (K, holotype!) ( Figure 1 ).

The species is illustrated in Flora Zambesiaca 4: Tab. 152 (p. 586) [as Aframmi longiradiatum ] and in Van Wyk et al. (2013, p. 239).

Distribution and habitat:— Angola, Zambia and Tanzania. According to notes on herbarium specimens, the plants occur on stony ground in grassland or open woodlands.

Specimens examined: — Angola: Foot of Serra do Ferreira de Amaral [perhaps Anhara?], on the eastern side, February 1907, Gossweiler 2829 (BM!, sheet 1). Serra de Moco [Morro de Moco], near river, 2000 m, Gossweiler 12284 (BM!).

Tanzania: T4 , Sumbawanga distr. : Tatanda Mission, 8 deg. 32 min. S ; 31 deg. 30 min. E, 1800 m. Shallow soil over small rocky outcrops in open Brachystegia woodland. Erect, single-stemmed perennial herb with short creeping rhizome, flowers yellow. 24 February 1994, S. Bidgood, F. Mbago & K. Vollesen 2424 ( K!) .

Zambia: Northern Province, Mbala distr.: Kalambo Falls, perennial, 1 m, flowers yellowish green, 29/3/1955, A. W. Exell, F. A. Mendonça & H. Wild 1281 ( BM). Abercorn [Mbala] distr.: Hill above Mwambe village , 1800 m, on steep rocky hillside, among rough grass and scattered trees ; umbels pale green and yellow, seeds dark brown, 15/3/1960, H. M. Richards 12746 ( K). Abercorn [Mbala] distr.: Kalambo Falls , 900 m, umbels pale yellow, stem pale green, 15/2/1964, H. M. Richards 19032 ( K). Lalambo Falls , top of the Gorge, 1200 m, woodland, steep bank, long grass ; umbels yellow, leaves finely pinnate, 16/2/1965, H. M. Richards 19697 ( K). Mbala distr.: Kalambo Falls , near car park, shady woodland, perennial to c. 80 cm, 23 February 1970, Drummond & Williamson 9965 ( BM, 2 sheets!, LISC, SRGH) .

Figures

FIGURE 1. Holotype of Normantha filiformis (Richards 5198, K) showing the divided, non-sheathing leaves with filiform segments and the slender peduncles and rays.

FIGURE 2. Fruits of Normantha filiformis (A), Heteromorpha arborescens (B) and H. gossweileri (C). A1, immature fruit (Richards 5198, K); A2, mature fruit (Richards 12746, K); A3, transverse section of mature fruit (Richards 12746, K); B1–3, mature fruit (Van Wyk s.n., JRAU): B1, two-winged mericarp; B2, whole fruit; B3, three-winged mericarp; B4, transverse section of mature fruit (Vlok 2633, JRAU); C1, transverse section of fruit (Gossweiler 4346, BM); C2, transverse section of young fruit (M. Koekemoer sub P.J.D. Winter 7792, PRE, LUBA). Scale bars = 1 mm.