Review of the three species accepted in Chortolirion A.Berger (Xanthorrhoeaceae: Asphodeloideae) Georg Fritz Abstract In a recent detailed study, the genus Chortolirion A.Berger was revised (Zon- neveld & Fritz 2010). Three species were subsequently accepted, namely the spring-flowering C. angolense (Baker) A.Berger, the autumn-floweringC. tenu- ifolium (Engl.) A.Berger, which was rein- stated, and the summer-floweringC. lat- ifolium Zonn. & G.P.J. Fritz, which was described as new. A summary of this re- vision is provided and new information that has since become available, includ- ing several new localities, is offered. Introduction In the past, Chortolirion has largely been studied from herbarium sheets. Limited fieldwork was conducted to investigate the inconsistent morphological charac- teristics observed on these herbarium records or to examine the differences between various populations seen in the field. It is noteworthy that, in the past, herbarium records of the species were not collected with a view to dis- tinguishing between spring- and au- tumn-flowering populations (Craibet al. 200). Failure to recognize obvious dif- ferences between various populations over the entire distribution has resulted in Chortolirion being considered a vari- able monotypic genus, with C. angolense the only species (Smith 1991, 1995; Craib et al. 200). All species later described, namely C. bergerianum Dinter, C. steno- phyllum (Baker) A.Berger, C. subspicatum A.Berger, C. tenuifolium and C. saundersii Baker nom. nud., were treated as syno- nyms. More recently, it has become obvi- ous that an extensive field-based study was required to account for the differ- ences encountered in Chortolirion popu- lations in the field by recognizing their distinctive autecologies, morphological differences and specific flowering times in spring, summer and autumn (Craib Figure 1. Bulbs of C. angolense (Fritz 1003) with inflorescences, flowers and fruit. 2005; Fritz 2007). ALOE 9:1:2012. ISSN 0002-6301 In search of Chortolirion State and North West Province. From These comparisons revealed that Chorto- time to time, 16 live specimens from lirion was best circumscribed as a genus During the first week of February 2008, different localities were sent to Dr. Ben with at least three species distinguished the late Charles Craib, who was an au- Zonneveld at the National Herbarium on the basis of distinctive flowering thority on Chortolirion populations in of the Netherlands, University of Leiden times, morphological differences and South Africa, and I travelled through Branch, for measurement of the genome specific habitat requirements (Table 1). Gauteng and Mpumalanga to collect size (nuclear DNA content). The rele- Vouchers of the newly collected plants living material of the autumn-flower- vant literature and original descriptions were deposited at the National Herbari- ing forms of Chortolirion. In 2009, we and illustrations published on Chortolir- um (PRE) of the South African National continued our field work and collected ion obtained from various sources, were Biodiversity Institute in Pretoria. specimens of the spring- and summer- studied and compared to all available flowering forms in Gauteng, the Free live material (Zonneveld & Fritz 2010). Table 1. Comparison between the three species of Chortolirion Feature C. angolense C. latifolium C. tenuifolium Flowering time RSA spring (Aug.–Sept.) summer (Nov.–Dec.) autumn (Feb.–Mar.) DNA in pg 27.2 30.6 27.2 (1picogram =10-12 gram) Inflorescence length 20–35 cm 30–100 cm 30–100 cm Inflorescence diameter 2–3 mm 3– mm 3– mm Leaf length 3–12 cm 5–12 cm 5–30 cm Leaf width 2 mm –5 mm 1–3 (–5) mm Leaf twist 2–5 times strongly spiralling Once Spots on leaf base present present Absent Leaf base tuberculate/spiny tuberculate/spiny Hairy Perianth (corona) colour whitish/greenish brown/beige brown/beige/whitish pale pink to coral-pink Perianth length 10–1 mm 15 mm 1–17 mm Pedicel length 1–2 mm 1–2 mm 3– mm Flower disposition semi-erect erect horizontal Number of flowers open 2–3 3–10 3–5 simultaneously Flowering before leaves leaves present leaves present Sterile bracts 2 × 9 mm 2 × 9 mm 5 × 12 mm Floral bracts 2 × 5 mm 2 × 5 mm × 7 mm Growth form single often clumping Single Bulb diameter 15–30 mm 15–30 mm 15–33 mm Habitat grassy plains/various soil types grasslands/sandy soils rocky grasslands central Free State/Gauteng/ Gauteng/Mpumalanga/ Distribution Angola/RSA North West Namibia Frequency common very rare Rare ALOE 9:1:2012. ISSN 0002-6301 5 1. Chortolirion angolense (Baker) 2. Chortolirion tenuifolium (Engl.) role in clearing habitat before flower- A.Berger in Das Pflanzenreich, A.Berger in Das Pflanzenreich, ing as the plants send up 1 m high in- IV.38. III: 73 (1908). IV.38. III: 73 (1908). florescences that protrude above the surrounding vegetation, thus aiding Haworthia tenuifolia Engl. in Engl. Bot. pollination by insects in flight. Plants Haworthia angolensis Baker in Trans. Linn. Jahrb. 10: 2. t. 1 (1889); Baker in Th. Dyer always grow singly in rather scattered Soc., ser. 2, 1: 263 (1880 but pub. 1878); Fl. Cap. 6: 355 (1896); R.A.Dyer in Flower- populations of 10 to 30 plants. A distin- Baker in Th. Dyer Fl. Trop. Afr. 7: 69 ing Plants of South Africa 2: t. 932 (19). guishing character of C. tenuifolium is (1897). Holotype: Welwitsch 3756 (BM). Holotype: Marloth 1049 (B). the large (up to 17 mm long), pale pink Haworthia subspicata Baker in Bull. Herb. Chortolirion stenophyllum (Baker) to coral-pink flowers carried horizon- Boiss. : 998–9 (190). Holotype: Conrath A.Berger in Das Pflanzenreich, IV.38. III: tally when fully open. These attractive 645 (Z). 72 (1908); R.A. Dyer in Flowering Plants flowers somewhat resemble those of of South Africa 2: t. 932 (19). Haworthia Aloe compressa, and are less haworthia- Chortolirion angolense is a common sum- stenophylla Baker in Hook. Icon. Pl. 10: t. like than those of C. angolense and C. lati- mer-rainfall grassland species in South 197 (1891); Baker in Th. Dyer Fl. Cap. 6: folium. The long, narrow, greyish-green, Africa, growing singly in small colo- 355 (1896). Holotype: Galpin 858 (K). immaculate (spotless) leaves are hairy nies or scattered over a wide area. It is at the base, in contrast with the tubercu- well adapted to various soil types and Chortolirion bergerianum Dinter in Neue late and spiny leaf bases of the other two to an annual winter grass-fire cycle. und weinig bekannte Pflanzen Deutsch- species mentioned. These fires open up and clear the habi- Sudwest-Africas: 2 (191). Holotype: tat, enabling an early flowering period Dinter 4295 (B). Although C. tenuifolium may have a from August, before any leaves have ap- wide distribution in the summer-rain- Chortolirion saundersiae Baker nom. nud. peared or spring rains have fallen – this fall area of South Africa, it is still not a in Hook Icon. Pl. 10: t. 191 (1891). is typical of pre-rain flora (Figure 1). The well-known species and may as well oc- inconspicuous flowers are carried on a In Gauteng and Mpumalanga the rare C. cur in neighbouring countries such as 20–35 cm long simple inflorescence (Fig- tenuifolium is found on rocky sandstone Namibia, Botswana and Zimbabwe. ure 2). By October, the plants are in fruit and quartzite plates and outcrops, the Locality at Jameson Park, Heidelberg, and the brief growing cycle is completed rocky habitats protecting these plants Gauteng. before the plants become smothered by against bulb-eating rodents such as por- taller grasses. C. angolense was formerly cupines. C. tenuifolium starts its grow- Plants of this species were unexpectedly common around Heidelberg, Gauteng, ing cycle later, in early summer, after discovered by the author in February but in recent times many colonies have adequate rain has fallen. The leaves are 200 (Fritz 2005) while searching for disappeared as a result of the expansion fully grown by the time flowering com- new localities of Khadia beswickii grow- of suburbs, as is the case in many parts mences in February and March. For this ing at Jameson Park, Heidelberg, Gau- of its distribution within this province. species, fire does not play a significant teng (Figure 3). It was quite a surprise to Figure 2. Two flowering plants of C. Figure 3. A large plant of C. tenuifolium (Fritz Figure . C. tenuifolium, with its raceme of angolense (Fritz 1002) growing close together 1022) growing among clumps of Khadia pinkish horizontally disposed flowers with in burnt grassland. It usually flowers before beswickii. Note the long, narrow, immaculate open mouths. the first spring rains. leaves and peduncle mm in diameter 6 ALOE 9:1:2012. ISSN 0002-6301 find a Chortolirion flowering at that time of year, carrying striking pinkish flow- ers (Figure ) on a simple inflorescence 1 m tall! A peculiar phenomenon is that many plants were found on termite mounds, between and among clumps of K. beswickii. It seems that the well-pro- tected, composted spaces between the leaves of these khadias offer excellent conditions for germination of the seed. Three populations of C. tenuifolium are known in this area, invariably growing in association with the khadias as well as with Gladiolus permeabilis and the small white-flowered Nerine rehmannii. Locality east of Delmas, Mpumalanga. As experienced at most localities of C. tenuifolium, few plants are scattered in a small area at the Delmas locality where plants are quite robust, while the flow- ers are pale pink to whitish. Locality near Bronkhorstspruit, Gau- teng. Figure 5. Plants of C. tenuifolium (Fritz 1020) from the Bronkhorstspruit locality. At this locality C. tenuifolium grows scat- tered in flat grassland in shallow sandy soil and gravel patches at the edge of A very miniature form of C.
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages7 Page
-
File Size-